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Policy Analysis
The Role of Public Policy in Technology Diffusion: The case of Plug-in Electric Vehicles Julio C. Zambrano-Gutiérrez, Sean Nicholson-Crotty, Sanya Carley, and Saba Siddiki Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b01149 • Publication Date (Web): 07 Sep 2018 Downloaded from http://pubs.acs.org on September 11, 2018
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The Role of Public Policy in Technology Diffusion: The case of Plug-in Electric Vehicles Julio C. Zambrano-Gutiérrez*, †, Sean Nicholson-Crotty†, Sanya Carley†, Saba Siddiki‡ †
School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405, USA Maxwell School of Citizenship and Public Affairs, Syracuse University, Syracuse, NY 13244, USA * Corresponding author’s email:
[email protected] ‡
10 11 12
Abstract The plug-in electric vehicle (PEV) is regarded by many as a viable alternative to the
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internal combustion engine, so long as the radical technology is able to overcome technical and
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financial shortcomings that dictate consumer acceptance. States have instituted a variety of
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policies aimed at mitigating these shortcomings and simultaneously increasing consumer demand
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for PEV vehicles. Motivated by a limited body of literature on the effects of these policies, and a
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significant need for information about policy efficacy, in this study we evaluate the relationship
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between a suite of state-level policies and PEV registrations. Results reveal that tax credits for
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individuals, grants programs for charging infrastructure and PEV purchases, and incentives for
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state-owned PEVs fleets increase PEV registrations. The observed impact of grant incentives is
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mediated by charging capacity or, alternative phrased, much of the influence of grants on
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registrations is through the channel of first improving the charging infrastructure within a state. Abstract Art PEV registrations (thousand)
23 120 100 80 60 40 20 0 2010
2011
2012
2013
2014
2015
States with no incentives States with at least one incentive
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Introduction
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The plug-in electric vehicle (PEV) is a classic case of a radical technology. It is touted for
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its potential to compete with, and potentially displace, the internal combustion engine (ICE) as a
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dominant vehicle technology. As with other “radical” technologies (1), however, this
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technological shift will require a confluence of policy, infrastructural, and behavioral
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developments in its favor. Generally speaking, scholars interested in the adoption and diffusion
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of product innovations have long recognized that government policies can encourage shifts in
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consumer preferences toward them (2-4). Work on radical technologies suggest that these
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“pushes” from government are particularly important when an innovation represents something
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truly new or radical to the current technological regime with which consumers are familiar (5-6). The first mass-marketed PEVs hit the U.S. automobile market in 2010. As of 2016, the
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stock of PEVs had grown to 563,710 (7), with uneven distributions of these vehicles across
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states. A number of factors are known to dissuade potential consumers from adopting PEVs,
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including cost, range, and battery recharging requirements (8-9). PEVs tend to have an upfront
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cost that is 50 to 100% higher than similar internal combustion engine vehicles, though the level
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of subsidies offered by government affects what the consumer pays (8). The range of most
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current PEVs on a fully-charged battery without a hybrid engine is typically between 70 and 100
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miles, significantly less than the 250- to 350-mile range of a conventional ICE. These distance
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limitations contribute to “range anxiety” (8), a fear that one’s battery will die when on the road.
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Finally, PEVs require specific charging infrastructure that must be installed in an owners’ home
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or an accessible public facility. Previous work on the intent to purchase PEVs (10) find that
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perceptions of these disadvantages damage consumer interest in adoption more than any other
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factor.
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States and municipalities have adopted a number of policies designed to overcome these
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barriers and facilitate PEV consumption, though the policy response varies considerably across
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jurisdictions. Not surprisingly, there have been a number of studies of the relationship between
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these policy incentives and the spread of PEVs; but these studies have reached mixed
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conclusions about policy impacts (see 11-12 for a recent review of many of these studies). A
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number of studies have also surveyed consumers and potential consumers in order to understand
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the impact of policies (see for example 13-14) and this methodological approach has also
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produced mixed conclusions. However, in the interest of brevity, we will only provide a partial
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review of studies that examine policy impact using statistical analyses to predict actual PEV
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purchases or registrations.
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Several studies have focused exclusively on the most prominent policy incentives for
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PEV purchase – direct financial incentives and charging infrastructure. Sierzchula et al. (15) find
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that both are important, but that neither has a particularly large impact on PEV purchases. Lutsey
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et al. (16) identify an interactive effect between these variables, suggesting that financial
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incentives are positively associated with PEV sales, but only in states with sufficient charging
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availability. A key drawback to both of these studies, however, is that they are estimated in a
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single year of data and, as such, cannot include fixed effects to account for time or unmeasured
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state-level characteristics, including other policies.
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Li et al. (17) also focus on tax incentives, in the form of the federal income tax credit, and
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municipal level charging capacity. They adopt a more sophisticated design, examining quarterly
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sales over a two-year period and explicitly accounting for endogeneity between previous PEV
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sales and investment in charging infrastructure. Because of the longer time frame, they are also
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able to estimate a two-way fixed effects model, which helps to isolate within-jurisdiction effects.
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However, it is important to note that fixed effects cannot account for state-level policy incentives
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that are time-variant but otherwise omitted from the analysis, such as grant programs and
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incentives for state-owned PEVs fleets. Li et al. found that federal incentive does increase sales,
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but that almost half of the effect is due to charging capacity, and that a direct incentive for
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charging station deployment would have a larger overall effect on PEV consumption.
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Some studies have also sought to analyze the impact of a larger suite of PEV related
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policy incentives, but again, report varying results. Studies have found a positive association
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between financial incentives, investment in charging infrastructure, high occupancy vehicle
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(HOV) lane access, and, in one case, emissions testing exceptions (18-19). Vergis and Chen (20)
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examine the impact of purchase incentives and a count of other “supportive” policies, but do not
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distinguish the individual policies. They find a positive correlation between these variables and
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market share for battery electric vehicles, but not for plug-in hybrid electrics. These results are
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the opposite of those arrived at by Jin et al. (19). Santini and colleagues (21-22) find that DOE
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grants affected state-level registrations in the absence of other policies, while activities by public
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utilities to promote PEVs only worked in conjunction with other state-level incentives. This latter
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result is consistent with Slowik and Lutsey (23), who suggest “a comprehensive package of
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policy and promotion actions by state, local, utility, and other private stakeholders is a key for
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developing the electric vehicle market.” Unfortunately, all of these studies employ a cross-
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sectional research designs in a very limited study period and, thus, cannot isolate within-
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jurisdiction effects.
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Clinton et al. (24) analyze sales over a slightly longer time period—two years—and find
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that tax credit and charging infrastructure are significant predictors, while direct rebates and
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HOV lane access are not. These authors use an instrumental variables approach to deal with
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endogeneity between sales and charging infrastructure. Unfortunately, the financial incentives
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analyzed by Clinton et al. do not vary over the short time span of their study, so they were unable
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to estimate within-state effects.
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Jenn et al. (25) confirmed the positive effect of financial incentives (tax credits and
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rebates) on the number of PEVs registrations. They also find that consumer awareness of
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incentives helps to explain heterogeneity in the response to them. These authors test the effects
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of PEV incentives during a longer period (2010-2015) and adopt a sophisticated methodological
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approach. Unfortunately, because of the use of monthly data, they cannot explicitly include
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charging infrastructure and PEV model availability in their models.
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We suggest that mixed findings in previous research regarding the impact of public
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policies on PEV market share, along with uncertainty regarding the best way for governments to
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incentivize the spread of this technology, are due to inconsistencies in the design of previous
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studies. Studies to date tend to focus on sales in a single year or limited number of years,
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evaluate a limited number of policy incentives, or employ methodological approaches that
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compromise internal validity. In our analysis, we seek to build on these studies by analyzing a
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larger number of policies, more PEV models, over a much longer period of time, and using an
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identification strategy aimed at causal inference and the use of mediated or indirect impacts of
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policy on the spread of PEVs.
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More specifically, we analyze the effect of nine policy incentives on the spread of PEVs
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between 2010 and 2016. We find that tax credits for individuals, grants programs targeting
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charging infrastructure and the purchase of PEVs, and incentives for state-owned PEVs fleets
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increase registrations even when controlling for other incentives. We also find that the observed
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impact of grant incentives is mediated by charging capacity or, more specifically that much of
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their influence on registrations comes through their role in improving the charging infrastructure
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within a state. The paper concludes with a discussion of the implications of these results for our
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understanding of the diffusion of radical technologies and the ability for systems to overcome
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technological “lock-in” (26). Methods
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We examine PEV registrations in the American states between 2010 and 2016 because
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this time frame spans from the introduction of modern PEVs through the last year for which data
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are currently available. Our dataset is a longer time series than has been used in previous studies
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and the set of PEV adoption policies—nine in total—is more extensive than those studied
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previously. Following the precedent set by previous scholars (17,24), we employ a
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methodological approach that accounts for endogeneity between charging infrastructure and PEV
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sales. We also employ a research design that allows us to investigate the degree to which the
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impact of policy on PEV diffusion actually operates through its impact on charging
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infrastructure.
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Dependent Variable: PEV Registrations
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The data for new PEV registrations come from the private provider, IHS Markit (27).
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They include information for battery electric vehicles (BEV) and plug-in hybrid electric vehicles
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(PHEV) registrations for each year between 2010 and 2016 by state. This study includes 50 PEV
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models but does not include data on low-speed electric vehicle registrations, since their
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technology is not comparable with the mass marketed PEVs.
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The primary dependent variable for this study is the number of annual new PEV
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registrations by state. As displayed in Figure 1, the spread of PEVs has been unequal between
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states. The state of California accounts for 48% of the total new PEVs registrations accumulated
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between 2010 and 2016, followed by Georgia with 5%; and Washington, New York, and Florida
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each one with approximately 4% of the PEV registrations. The rest of states have a participation
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between 0.02% (Wyoming) and 3.19% (Texas) of the new PEV registrations during our seven
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years of analysis. [Figure 1 here]
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Independent Variables: Public Policies Data on PEV related policies come from LexisNexis State Capital (28), which provides
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access to legislative statutes from the fifty states. Using keywords “low emission vehicles OR
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zero emission vehicles OR electric vehicles”, we found 150 out of 557 relevant results
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containing information related to PEV incentives between 1990 and 2016. Search results that are
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not part of this study only provide definitions about our keywords (70%) or do not contain new
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information about policy incentives (30%). The history of the modifications in the statutory
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codes are available and linked to a respective bill; the latter of which contains the year the policy
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went into effect. In some occasions (30% of the useable cases), the bill only contains the
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adoption year, in which case this study assumes that the following year is the effective year.
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Our data extraction technique identified a total of 24 different types of PEV incentives at
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the state level. Many of these policies, however, had diffused to only a single state or were
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adopted long before modern PEVs hit the market, making assessments of their causal impacts
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impossible. In our analyses, we chose to focus on nine public policies that diffused to two or
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more states and were adopted by at least two states after 2010. Figure 1 reveals that, like PEVs,
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the spread of these nine policies among the states has been uneven. The policies include financial
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incentives, infrastructure related incentives, and symbolic policies as fully described in Table 1.
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[Table 1 here]
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We use data on PEV incentives to create two different types of independent variables.
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First, we create dichotomous indicators coded 1 if a state has a particular policy and 0 otherwise,
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which allows us to estimate the impact of adopting an individual policy while controlling for the
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adoption of other policies. Afterwards, we code the dollar amounts of grants and tax credits to
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explore whether the size, rather than simply the presence, of a financial incentive influences the
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number of PEV registrations within a state.
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Control Variables
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We control for internal state characteristics that may influence both PEV diffusion and
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PEV policy adoption. The control variables represent obstacles and motivations to the adoption
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of new technology by consumers within a state. All data sources are outlined in Table 2. One of
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the primary impediments to the spread of PEVs identified in previous research is extent of the
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charging infrastructure within a jurisdiction. In order to capture that capacity, we create a
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measure of the number of charging stations in each state and year.
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This study includes a measure of PEV-models available in each state in each year to
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control for the influence of supply on PEV diffusion. Consistent with previous studies, we expect
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higher number of PEV registrations in states with a larger number of PEV models available (16).
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Because of their expense, both in terms of purchase price and investment required by
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communities, there are also likely to be a number of socioeconomic obstacles to the spread of
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PEVs. We capture these with measures of wealth, education and, employment. Specifically, we
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measure gross state product (GSP) per capita, the proportion of the population with at least high
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school education, and the unemployment rate.
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Citizens may also purchase PEVs in an effort to reduce negative environmental
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consequences of ICEs, such as carbon dioxide (CO2) emissions. This analysis includes the CO2
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emissions produced by the transportation sector as a proportion of the total CO2 emissions at
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each state. States with higher proportion of CO2 emissions are expected to have a higher level of
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PEV registrations. The data for CO2 emissions are only available until 2014 (38), therefore we
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interpolate the values for 2015 and 2016 as a function of the GSP. One remark about PEVs is
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that their combustion emission take place during the stage of electricity generation (29-30). For
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that reason, we include renewable energy use within a state to capture the readiness of each state
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to embrace less pollutant technologies.
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Of course, the level of concern over issues such as CO2 emissions and the willingness to
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embrace technologies such as PEVs more broadly is likely to be partially a function of the
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environmental ideology of state residents. We capture this orientation with two political
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measures. The first is the percent of Democratic legislators in the Senate and House of
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Representatives. We also include the total number of victories of members from the Green Party
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across different popularly elected positions in each state.
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If one extends the literature on conventional hybrids to the context of the PEV, we could
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hypothesize that consumers in states with higher gasoline prices are more likely motivated to
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accept PEVs as an ICE alternative than those that live in states with lower gasoline prices (31-
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33). We include annual data for average gasoline price per gallon, which incorporates federal and
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state gasoline taxes, but excludes local taxes. In a related argument, previous work has assumed
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that the price of electricity will influence the decisions of consumers considering PEVs.
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Therefore, we control for the average price for electricity (cents/kilowatt-hour) in each state and
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year. Finally, the number of licensed drivers operationalize the size of the potential market for
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PEV at each state.
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[Table 2 here]
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Design and Estimators For the primary analysis, this study exploits variation in the timing and extent of PEV
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policy adoption in the American states in order to estimate a generalized difference-in-
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differences model. As is standard in these estimators, the model includes two-way fixed effects
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(FEs) which allows for the estimation of the within-state effects of a policy on PEV registrations
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in the period following its adoption. Standard errors are clustered at the state level in this
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specification. The basic estimator can be represented as such: = + .. + ′ + + + (1)
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Where: Yit = New Electric Vehicle Registrations in Statei at Timet Tit = Electric Vehicle Promotion Policyn..k Adopt * Post in Statei at Timet X’it = a vector of time variant control variables in Statei at Timet ui = a state fixed effect vt = a year fixed effect
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This specification allows us to compare PEV registrations within each state before and
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after the adoption of each PEV related policy, while controlling the existence of other policies
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and a host of controls.
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As noted above, previous work suggests that charging infrastructure within a jurisdiction
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not only incentivizes potential consumers of PEVs but may also be endogenous to previous sales.
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Diagnostics reveal that this is also the case in our sample of states and years. In order to correct
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for potential bias arising from this endogeneity, we implement an instrumental variables
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approach with the differences-in-differences framework. Following the suggestion of Li et al.
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(17), we instrument the number of charging stations with the interaction between the number of
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stations in all states other than the state-year observation under analysis and the number of
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grocery stores in each state (lagged one year). The first stage shows an F-test for the excluded
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instrument of 37.38, suggesting that the instrument is acceptable. So, in the equation discussed
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above, X’it –the vector of time variant control variables in Statei at Timet –contains the
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instrumented version of charging stations, rather than the actual number.
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Finally, we run a mediating variables analysis in order to determine whether the observed
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impact of PEV policies on sales is in part a function of their impact on charging infrastructure.
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Evidence of mediation requires us to show that: 1) the number of charging stations influences
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registrations; 2) policies influence the number of charging stations; 3) policies influence
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registrations in the absence of a control for charging stations; and 4) the impact of policies on
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registrations changes when we include the mediator in the model. The first of these requirements
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can be met in our primary analysis presented in Table 3 (Column 1). We test for number 2 in a
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two-way fixed effects model where number of charging stations is the dependent variable, which
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is presented in the first column of Table 4. The last two requirements are tested with difference-
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in-difference models of registrations presented in columns 2 and 3 of that table. We instrument
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for charging stations in the last model because we still need to correct for diagnosed endogeneity.
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Thus, the final analysis in Table 4 is identical to the main model presented in Table 3 (Column
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2), but we present it again in order to facilitate the observation of any mediating effects.
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Results The first column of Table 3 contains the difference-in-differences analysis of the impact
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of nine policy incentives on PEV registrations between 2010 and 2016. Consistent with previous
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work, instrumented charging infrastructure has a significant and positive impact on registrations.
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The results suggest that a 1-standard deviation increase in charging stations is associated with a
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5,360 or 0.82-standard deviation increase PEV registrations. As another way to think about this
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result, it suggests that a 10% increase in available charging infrastructure (as measured by the
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instrumented charging stations variable) is associated with approximately 18 % more
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registrations.
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When we use a dichotomous indicator of policy, the results suggest that tax credits for
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individuals have a positive impact on the number of new PEV registrations in each state.
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Substantively, the findings suggest that the adoption of tax credits for individuals causes 1977
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additional PEV registrations in adopting states, which represents an increase of more than 0.3 –
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standard deviations. Interestingly, the findings also suggest that the presence of special financing
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for PEV related equipment increases PEV registrations in a state and that the impact is larger
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than that of individual tax credits. Specifically, we find that state guaranteed financing increases
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registrations by 5,452 or 0.83-standard deviations compared with the level prior to adoption.
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Finally, we find that the adoption of incentives for state-owned PEV fleets causes an increase of
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2,115 PEV registrations, which represents an increase of 0.32 – standard deviations.
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[Table 3 here] It is possible, of course, that a simple dichotomous indicator of polices obscures
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important variation in their impact on the spread of PEVs. Therefore, in order to generate a more
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precise estimate of the impact of grants and tax incentives, the second column of Table 3
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presents models that uses the dollar amounts of these financial incentives, rather than simply an
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indicator of their presence. When we take the dollar amounts into account, both monetary
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incentives cause an increase in PEV registrations, and grants now appear to have a larger impact
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than tax credits. Specifically, we find that the adoption of a $5 million program, which is the
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median size among states with these programs, results in increase of 6,500 in PEV registrations
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relative to the period before adoption, which represents almost a full standard deviation increase.
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Alternatively, adoption of the median tax credit of $6,000 increases registrations by 653, which
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is or about 0.1 – standard deviations.
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Before moving on, it is important to note that three policies had a negative and significant
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impact on PEV sales. Specifically, models suggest that states that adopted regulations intended
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to standardize public charging stations within a state, states in the planning stage, and those that
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adopted policies reserving special parking spots for PEV drivers actually saw a decrease in new
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registrations following those adoptions. We will return to these negative findings in the
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discussion section, where we offer some potential explanations.
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Exploring the mediating impact of charging infrastructure
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The results thus far suggest that policies designed, at least in part, to contribute to a
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state’s charging infrastructure may have an influence on PEV registrations. This raises the
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possibility that this observed impact is in fact mediated by the degree to which these policies
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actually increase the number of stations available to PEV owners.
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The analyses presented in Tables 3 and 4 provide the information necessary to test that
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possibility. First, the primary analysis presented in the first column of Table 3 confirms that
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charging stations (instrumented) have a positive and significant impact on PEV registrations.
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Turning now to Table 4, the two-way fixed effects model of charging stations in the first column
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shows that some public policies do have an impact on charging infrastructure, which is the next
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prerequisite for demonstrating a mediating effect. Specifically, the analysis suggests that the
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presence of grants that can be used to enhance charging capacity are positively associated with
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the number of charging stations within a state.
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[Table 4 here]
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The final piece in the mediating variables analysis is to compare the impact of these
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policies on registrations when the potential mediator—number of charging stations—is excluded
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versus included in the models. Looking at the final two columns of Table 4 we can see that
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grants increase registrations in both models, but that the impact shrinks significantly when the
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instrumented charging station variable is included in the model. Specifically, the results suggest
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that 46% of the total impact of PEV grant policies on new registrations actually comes through
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the increase in available charging capacity that the policy stimulates. Discussion
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There has been significant growth in the ownership of PEVs since the first mass-
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marketed models became available in 2010. That diffusion has, however, been highly variable
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across states. Incentives to facilitate the spread of PEVs have also varied dramatically across the
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states and we test whether heterogeneity in the latter can explain the observed variation in the
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former. This study represents a contribution to existing research on this subject because it
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investigates a larger number of PEV related policies, over a longer time period, using causal
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identification strategies that explores both direct and mediated effects of public policy.
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Analyses of PEV ownership and nine PEV statutory policy-incentives across all 50 states
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between 2010 and 2016 provide some evidence for the positive role of government incentives on
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PEVs uptake. Specifically, they suggest that the adoption of grants targeting infrastructure and
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ownership, as well as policies creating special financing for PEV-related equipment increase
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PEV registrations within a state. These policies remain the significant predictors of registrations
321
even if we use the dollar amounts of financial incentives, such as grants and tax credits, as the
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independent variables.
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These results offer an important confirmation of previous findings which suggest that
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individual tax credits can spur PEV diffusion, even when we control for a much larger number of
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policies and analyze registrations over a much longer time period. They also add significantly to
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previous work by suggesting that other policies can also influence PEV registrations. Indeed, the
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findings indicate that states may be able to overcome the observability problem inherent in new
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technologies such as PEVs simply by putting these vehicles on the road in public fleets.
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Interestingly, the influence of incentives for state-owned electric fleets on new registrations is
330
larger than the impact for individual tax incentives, which have been one of the most widely
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touted mechanisms for incentivizing uptake of PEVs.
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The findings also suggest the import of another heretofore unexplored state-level
333
incentive for PEV diffusion. Specifically, they suggest that grants targeted at improving charging
334
infrastructure and providing better financing for PEV purchases have a positive and significant
335
impact on new PEV registrations in the states that adopt them. Intuitively, we would expect that
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part of this impact would occur because they actually do improve charging capacity and a
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mediating variables analysis suggests that this is the case. The grants are positively associated
338
with the number of charging stations, which in turn is positively associated with PEV
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registrations. The final part of the mediating variable analysis suggests that almost half of the
340
observed treatment effect of adopting a PEV grants policy is, in fact, working through the impact
341
of those policies on charging capacity.
342
Before moving on, it is important to note that the impacts of individual tax credits or
343
policies to grow state-owned PEV fleets are not moderated by charging infrastructure. This is
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what we would expect, because these policies are not designed to overcome the barriers to PEV
345
ownership by improving charging capacity. The fact that they are not mediated by the number of
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stations provides a good falsification test and, therefore, increase our confidence in the validity
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of the results of the mediating variables analysis.
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Our results also suggest that numerous policy incentives do not appear to directly
349
increase PEV registrations. Of course, we exercise caution in interpreting these nonfindings, as
350
well as the positive results discussed above, because we are analyzing only six years of data at
351
the very outset of diffusion period for PEVs. Nonetheless, the failure of some of these policies,
352
like laws providing some funding to PEV manufacturers for R&D, to influence sales should not,
353
perhaps, be surprising. The mechanisms by which these policies might influence consumer
354
behavior in a meaningful way are difficult to imagine.
355
It is harder to understand why policies that seek to improve charging infrastructure by
356
standardizing charging stations within a state would not have a positive impact on PEV
357
registrations. However, these public charging station policies have actually increased the number
358
of charging stations (see Column 1, Table 4). As such, these policies help to reduce anxiety
359
among consumers about the range of PEVs. The fact that these policies appear to cause a
360
significant reduction in new registrations is more difficult to explain. It is possible that the debate
361
over these policies makes consumers aware that even if they find a charging station, they may
362
not be able to plug their new vehicle into it, which creates additional uncertainty and hampers the
363
diffusion of the technology. Obviously, however, more research is needed to understand the
364
mechanisms underlying this counter-intuitive result.
365
Previous research on PEVs suggests that price and range anxiety are the two major
366
factors that keep potential consumers from these vehicles. Older work also suggests that
367
observability is one of the key impediments to the spread of any truly innovative or novel
368
product (see Rogers (2)). Our findings indicate that policies that directly address these barriers
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are most effective at facilitating the spread of this radical technology. Tax incentives directly
370
reduce the higher price of PEVs; grants targeting charging infrastructure likely reduce range
371
anxiety because they actually increase the number of available charging stations; finally, policies
372
that grow state-owned PEV fleets allow consumers to see and become accustomed to the new
373
technology.
374 375
Acknowledgments
376
This article is part of a project funded by the National Science Foundation, under grant
377
award #1633082. Besides their appreciation for the financial support, the authors would also like
378
to acknowledge the helpful feedback offered by anonymous reviewers and other project team
379
members: Derek Ehrnschwender, Steven Kakovik, Amani Khoury, and Lucas Stegemiller.
380
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Figure 1. Accumulation of new Plug-in Electric Vehicles (PEVs) registrations (market share %) and PEV Policy-incentives (number of policies) between 2010 and 2016
490
491 492 493 494 495
Source: Upper panel: IHS Markit (27); lower panel: LexisNexis State Capital (28); this figure was created using ArcMap 10-6 (44).
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Table 1. Plug-in electric vehicle policy-incentives Category
Incentive
Description
Example
California with its Alternative and Renewable Fuel and Grant programs to finance the Vehicle Technology Program installation of electric vehicle and its Air Quality charging infrastructure and Improvement Program provides funding for electric the purchase of plug-in charging infrastructure and electric vehicles electric vehicle deployment up to $40 million per year
Grants
Tax credits for individuals to purchase or lease plug-in electric vehicles, and to Tax credits for individuals convert internal combustion engine vehicles into plug-in electric vehicles Financial
Electric vehicle supply equipment financing
Programs to issue bonds, notes and other types of financial instruments to finance the installation of electric vehicle charging station, electric vehicle conversions, and to support the deployment of plug-in electric vehicles
Colorado offers tax credits to individuals who own lowemission vehicles, including PEVs, for an amount up to $6,000 Alabama authorizes local governments to issue bonds, notes, or other type of financing methods to increase charging stations deployment
Financing research to South Carolina with its facilitate the development and Distributed Energy Resource commercialization of electric Program invests in vehicles and their parts, and technologies to improve the Research and development the investment in technologies load management of electric to improve load management vehicle charging of electric vehicle charging stations
Infrastructure
Public charging stations availability
Reduction of administrative Minnesota requires that any barriers to install electric installed electric vehicle vehicle charging stations, charging station must be requirements to have charging compatible for utilization with stations in interstate highway any type of electric vehicle rest areas, and compatibility (make, model) requirements to use charging stations for any type of electric vehicle
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Private charging stations availability
Parking availability
Planning
Symbolic
Reduction of administrative barriers to install electric vehicle charging stations for personal residential use
Oregon forbids homeowners associations to prohibit the installation of charging stations in a parking lot or in another area subject to the exclusive use of the owner
Hawaii mandates places with Assignation of parking spaces at least one hundred parking to plug-in electric vehicles spaces to designate no less and parking enforcement with than 1% of the parking spaces monetary penalties to electric vehicles Studies to evaluate the feasibility to deploy electric vehicles infrastructure, to purchase state-owned electric vehicle fleets, to reduce electricity rates to charge electric vehicles, and to use grid technology to facilitate the use of electric vehicles
Massachusetts requires an action plan to increase access to electric vehicle infrastructure, increment the purchase of PEV by reducing the cost of PEV purchase and identifying strategies to remove barriers to PEV deployment
Prioritize the purchase of new Connecticut requires that state-owned fleet to be plug-in alternative fuel cars must electric vehicles and to represent 50% of the lightIncentives for state-owned increase progressively the duty trucks purchase by the electric vehicles fleets proportion of plug-in electric state after 2008 and 100% vehicles in the state-owned after 2010 fleet 497 498
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499
Table 2. Descriptive Statistics (2010-2016) Variable
Mean
Std. Dev.
Min
Max
Source
1570.91
6577.5
0
74749
IHS Markit27
Dependent Variable PEV registrations
LexisNexis28
Independent Variables Financial incentives Grants
0.09
0.29
0
1
Grants (Million US$)
0.83
4.95
0
40.2
Tax credits for individuals
0.05
0.22
0
1
271.21
1425.14
0
15000
Electric vehicle supply equipment financing
0.06
0.24
0
1
Research and development
0.03
0.17
0
1
Public charging stations availability
0.07
0.25
0
1
Private charging stations availability
0.01
0.11
0
1
Parking availability
0.06
0.24
0
1
Planning
0.17
0.37
0
1
Incentives for state-owned electric vehicles fleets
0.20
0.40
0
1
1322.86
1817.68
105
10073
US Census Bureau34
Charging Stations
55.05
103.73
0
1180
Alternative Fuels Data Center35
PEV models availability (logged)
2.05
0.86
0.00
3.53
IHS Markit27
GDP (2010 USD Millions per capita)
0.05
0.01
0.03
0.08
Bureau of Economic Analysis36
Tax credits for individuals (US$)
Infrastructure incentives
Symbolic incentives
Instrumental Variable Grocery stores and supermarkets
Control Variables
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3.9
1.08
1.36
7.07
American Community Survey37
High school education (%)
29.01
2.95
23
38.23
American Community Survey37
C02 Transportation sector (% total emission)
35.78
11.7
11.44
60.17
Environment al Protection Agency38
99.77
U.S. Energy Information Administrati on39
91.14
National Conference of State Legislature40
69
Green Party Elections Database41
4.57
U.S. Energy Information Administrati on42
34.04
U.S. Energy Information Administrati on39
25.53
Federal Highway Administrati on43
Unemployed (%)
30.27
Renewable energy (% total energy)
48.09
Democrats in the legislature (%)
4.13
Green party victories
3.21
Gasoline price (USD)
Price of electricity (USD Cents/kilowatthour)
Licensed drivers (Millions)
10.42
4.26
23.13
17.31
8.99
0.56
3.87
4.43
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13.33
0
2.2
6.08
0.41
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501 502
Table 3. The effect of plug-in vehicle incentives on plug-in electric vehicle registrations (20102016) IV-FEs Grants
2543.3824 (2803.8188)
Tax credit for individuals
1976.8545*** (585.3514)
IV-FEs
Grants (US$)
0.0013*** (0.0004)
Tax credit for individuals (US$)
0.1089* (0.0464)
Electric vehicle supply equipment financing
5451.7439+ (2862.3421)
6080.6510 (3713.9809)
Research and Development
-505.6160 (855.6333)
-77.3595 (838.0104)
Public charging stations availability
-4231.1034*** (1041.4808)
-3448.6789*** (905.1473)
Private charging stations availability
-2666.7845 (2041.3897)
-2103.7550 (1903.5174)
Parking availability
-3470.3898+ (1917.8229)
-2883.3600 (1838.9848)
Planning
-2532.7464+ (1505.6860)
-2001.4547+ (1090.5485)
Incentives for state-owned PEVs fleets
2115.1354+ (1233.3533)
2148.7102+ (1210.0167)
Charging Stations
58.5555*** (10.2670)
51.6742*** (9.4720)
PEV models availability (logged)
638.3047 (575.1312)
485.0872 (476.9756)
-41059.2966 (83039.4611)
-49382.4971 (77673.3857)
Unemployed (%)
608.1368 (514.4131)
764.5352 (501.0593)
High school education (%)
429.9259+ (241.6774)
326.6275+ (195.6089)
GDP (2010 USD Millions per capita)
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CO2 Transportation sector (% total emissions)
-34.1718 (31.0155)
-39.9799 (32.2509)
Renewable energy (%total energy)
7.2845 (16.2786)
6.1597 (15.0851)
Democrats in the legislature (%)
8.9964 (28.0325)
19.8077 (26.5373)
Green Party Victories
52.0547 (55.7435)
24.0641 (37.8413)
Gasoline price (USD)
2889.9101 (3139.7872)
1654.2782 (2699.9509)
Price of electricity (USD Cents/kilowatt-hour)
303.3240 (329.4809)
161.7831 (223.1537)
Licensed drivers (Millions)
1606.5935 (1271.1941)
476.9607 (691.7363)
-32150.5230** -20751.7210* (12297.1416) (9833.2524) Observations 300 300 Clusters 50 50 State and Year fixed-effects Yes Yes First-stage F statistic 62.02 37.38 R2 within 0.7543 0.8063 Intra-class correlation 0.9452 0.9462 Cluster robust standard errors in parentheses: + p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001. Note: all independent variables are lagged one period except tax credits for individuals Constant
503 504
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505
Table 4. Mediating analysis: How charging stations affect PEV registrations? Charging Stations FEs
Registrations
Registrations
FEs
FEs-IV
Grants (Million US$)
0.0000*** (0.0000)
0.0028*** (0.0004)
0.0013*** (0.0004)
Tax credits for individuals (US$)
-0.0012 (0.0011)
0.0470 (0.0617)
0.1089* (0.0464)
EVs supply equipment financing
82.0947 (70.4815)
10346.3421 (7956.6310)
6080.6510 (3713.9809)
Research and Development
-17.2048 (25.4381)
-731.6256 (748.7901)
-77.3595 (838.0104)
Public charging stations availability
59.7012* (26.7834)
-167.9650 (764.7739)
-3448.6789*** (905.1473)
Private charging stations availability
19.2522 (64.5896)
-1790.4073 (1861.6065)
-2103.7550 (1903.5174)
Parking availability
62.4284* (25.8884)
684.4644 (922.5250)
-2883.3600 (1838.9848)
Planning
-6.1189 (24.0510)
-2207.0213 (1597.9537)
-2001.4547+ (1090.5485)
Incentives for state-owned PEVs fleets
-36.7757 (28.0414)
417.1600 (811.4772)
2148.7102+ (1210.0167) 51.6742*** (9.4720)
Charging Stations -27.7733+ (13.9910)
-1775.7621* (882.9396)
485.0872 (476.9756)
2836.8092 (2586.2965)
86478.2534 (79655.3885)
-49382.4971 (77673.3857)
Unemployed (%)
-23.3429* (10.6120)
-493.8797 (315.6300)
764.5352 (501.0593)
High school education (%)
-7.3525* (3.1919)
-9.7749 (154.1134)
326.6275+ (195.6089)
CO2 Transportation sector
-0.3410 (0.6426)
-30.3822 (43.2512)
-39.9799 (32.2509)
Renewable energy (%total energy)
-0.5519
-12.7263
6.1597
PEV models availability (logged)
GDP (2010 USD Millions per capita)
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(0.4662)
(15.5262)
(15.0851)
Democrats in the legislature (%)
0.8073+ (0.4778)
49.1744+ (29.0196)
19.8077 (26.5373)
Green Party Victories
-1.0197+ (0.5697)
-44.1037* (17.8213)
24.0641 (37.8413)
Gasoline price (USD)
184.3636 (171.3989)
9926.6873 (6927.6988)
1654.2782 (2699.9509)
Price of electricity
3.3564 (4.7780)
251.5893 (318.0826)
161.7831 (223.1537)
Licensed drivers (Millions)
85.4523 (71.6702)
4255.1217 (3338.6606)
476.9607 (691.7363)
-20751.7210* (9833.2524) Observations 300 Clusters 50 State and Year fixed-effects Yes First-stage F statistic 37.38 R2 within 0.7423 0.7073 0.8063 Intra-class correlation 0.9909 0.9926 0.9462 Cluster robust standard errors in parentheses: + p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001. Note: all independent variables are lagged one period except tax credits for individuals Constant
506 507
-736.0855 (775.4530) 300 50 Yes
508 509
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