We study the welfare impacts of 96 climate-related tax and spending policies. We extend and apply the marginal value of public funds (MVPF) framework, most notably providing a new method for incorporating learning-by-doing spillovers. We find subsidies for the production of clean energy (such as wind production tax credits) have higher MVPFs than all other subsidies in our sample, including EV subsidies. Conservation nudges have large MVPFs when targeting regions with dirty grids. Fuel taxes and cap-and-trade policies are highly efficient means of raising revenue. We also construct traditional cost-per-ton estimates and compare and contrast the lessons they provide.

Increasing evidence indicates the importance of management in determining firms' productivity. Yet causal evidence regarding the effectiveness of management practices is scarce, especially for skilled labor in the developed world. In a field experiment measuring commercial airline captains’ productivity, we test four distinct management practices: performance monitoring, performance feedback, target setting, and prosocial incentives. These practices—particularly monitoring and target setting—significantly increase captains' productivity on the targeted fuel-saving dimensions, with positive spillovers on job satisfaction and CO2 emissions. The study reveals an uncharted research opportunity to delve into the black box of firms to examine the determinants of productivity among skilled labor.

Tax authorities often leave the consequences of non-compliance unspecified. We examine how disclosing those consequences affects tax payment and income reporting in four experiments. In a field experiment with HM Revenue and Customs, letters randomized to more than 200,000 taxpayers with outstanding income-tax debts increased payment when they warned of unspecified further action. Messages specifying financial or administrative costs did not produce the same benefit. An online payment experiment with 2050 taxpayers across fourteen conditions, including 1194 in the principal factorial design, found that revealing the maximum fine lowered the stated likelihood of paying. The reduction occurred at both modest and severe revealed maxima. It also occurred among participants who learned that the fine exceeded their prior estimate, contrary to the prediction from belief updating. An incentivized experiment with 827 participants extended the effect to income declarations with money at stake, although declarations differed between the two disclosed maxima in this setting. A laboratory experiment with 239 participants recorded differences in pupil dilation across enforcement messages without detectable differences in measured visual attention. Together, the findings suggest that ambiguity about enforcement consequences contributes to compliance. The physiological evidence is consistent with an affective account of this relationship. Disclosing a maximum penalty can therefore have a behavioral cost that tax authorities should consider when communicating enforcement policy.