We formalize a research design to uncover the mechanisms underlying long-term reductions in energy consumption caused by a widely implemented nudge. We consider two channels: technology adoption and habit formation. Using data from 38 natural field experiments, we isolate the role of technology adoption by comparing treatment and control homes after the initial resident moves, which discontinues the treatment for a home. We find that fully half of energy reductions persist in the home after treatment ends and show this persistence is consonant with a technology adoption channel. The role of technology in creating persistent behaviour change has important implications for designing behavioural interventions and evaluating their long-term social impacts.

Economic theory suggests that energy subsidies can lead to excessive consumption and environmental degradation. However, the precise impact of energy subsidies is not well understood. We analyze a large energy subsidy: the California Alternate Rates for Energy (CARE). CARE provides a price reduction for low-income consumers of natural gas and electricity. Using a natural field experiment, we estimate the price elasticity of demand for natural gas to be about −0.35 for CARE customers. An economic model of this subsidy yields three results. First, the natural gas subsidy appears to reduce welfare. Second, the economic impact of various policies, such as cap-and-trade, depends on whether prices for various customers move closer to the marginal social cost. Third, benefits to CARE customers need to increase by 6 percent to offset the costs of the program.

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.

Public recognition is frequently used to motivate desirable behavior, yet its welfare effects—such as costs of shame or gains from pride— are rarely measured. We develop a portable empirical methodology for measuring and monetizing social image utility, and we deploy it in experiments on exercise and charitable behavior. In all experiments, public recognition motivates desirable behavior but creates highly unequal image payoffs. High-performing individuals enjoy significant utility gains, while low-performing individuals incur significant utility losses. We estimate structural models of social signaling, and we use the models to explore the social efficiency of public recognition policies.

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.