Lucas Woodley’s research while affiliated with Harvard University and other places

New tailpipe emissions standards aim to increase electric vehicle (EV) sales in the United States. Here, we analyze the associated critical mineral supply chain constraints and enumerate the climate consequences of these constraints. Our work yields five findings. First, the proposed standard necessitates replacing at least 10.21 million new internal combustion engine vehicles with EVs between 2027 and 2032. Second, based on economically viable and geologically available mineral reserves, manufacturing sufficient EVs is plausible and reduces up to 457.3 million tons of CO2e. Third, mineral production capacities in the United States and amongst allies support the deployment of 5.09 million vehicles between 2027 and 2032, well short of compliance target. Fourth, this shortfall produces at least 59.54 million tons of CO2e in lost lifecycle emissions benefits. Fifth, limited production of battery-grade graphite and cobalt may represent particularly profound constraints. Pathways that afford comparable emission reductions are subsequently explored.

Procurement incentives are a widely leveraged policy lever to stimulate electric vehicle (EV) sales. However, their effectiveness in reducing transportation emissions depends on the behavioural characteristics of EV adopters. When an EV is used, under what conditions and by whom dictates whether or not these vehicles can deliver emissions reductions. Here, we document that replacing gasoline powered vehicles with EVs may—depending on behavioural characteristics—increase, not decrease, emissions. We further show that counterfactual vehicle inventory—how many vehicles a household would own absent an EV purchase—is an important influencer of these effects. We conclude that achieving emissions reductions using EVs requires redesigning procurement incentive programmes in a manner that (re)distributes incentives towards the second-hand EV market. Doing so would not only facilitate emissions reductions but also address fiscal prudency and regressivity concerns associated with these programmes.

Government efforts to address child poverty commonly encompass economic assistance programs that bolster household income. The Child Tax Credit (CTC) is the most prominent example of this. Introduced by the United States Congress in 1997, the program endeavors to help working parents via income stabilization. Our work examines the extent to which the CTC has done so. Our study, which documents clear, consistent, and compelling evidence of gender inequity in benefits realization, yields four key findings. First, stringent requisite income thresholds disproportionally disadvantage single mothers, a reflection of the high concentration of this demographic in lower segments of the income distribution. Second, married parents and, to a lesser extent, single fathers, are the primary beneficiaries of the CTC program when benefits are structured as credits rather than refunds. Third, making program benefits more generous disproportionally reduces how many single mothers, relative to married parents and single fathers, can claim this benefit. Fourth and finally, increasing credit refundability can mitigate gender differences in relief eligibility, although doing so imposes externalities of its own. Our findings can inform public policy discourse surrounding the efficacy of programs like the CTC and the effectiveness of programs aimed at alleviating child poverty.