Research

Many people think they can at most have a small impact on climate change through their own actions, limiting the demand for individual emission reductions. Currently available statistics are not suited to systematically assess this belief. In this paper, I derive the marginal impact of emission reductions – the effect of reducing emissions by 1tCO₂ – for tangible climate change outcomes, document important misperceptions and show how they affect behaviour. Using climate models, I estimate the marginal impact for glacier ice melting, life expectancy and vegetation change. Subjects’ beliefs are inconsistent with the climate model findings in several ways. First, they substantially underestimate the marginal impact. Second, they think the marginal impact increases when others reduce their emissions (strategic complementarity). By contrast, for most outcomes, climate models predict strategic substitutability. Third, they falsely believe there are discontinuities at known temperature thresholds, after which the marginal impact significantly decreases. Providing subjects with the climate model findings causally increases perceived self-efficacy, intentions to reduce emissions and real donations to mitigate them. The findings are consistent with a model of threshold thinking, which predicts positive overall reductions of information provision in equilibrium.

A key issue in science is assessing robustness to data analysis choices, while avoiding selective reporting and providing valid inference. Specification Curve Analysis is a tool intended to prevent selective reporting. Alas, when used for inference it can create severe biases and false positives, due to wrongly adjusting for covariates, and mask important treatment effect heterogeneity. As our motivating application, it led an influential study to conclude there is no relevant association between technology use and teenager mental well-being. We discuss these issues and propose a strategy for valid inference. Bayesian Specification Curve Analysis (BSCA) uses Bayesian Model Averaging to incorporate covariates and heterogeneous effects across treatments, outcomes and sub-populations. BSCA gives significantly different insights into teenager well-being. It provides strong evidence that technology has relevant associations with teenager well-being: (1) well-being is negatively associated with electronic device usage, (2) social media use is negatively associated with self-assessed well-being but positively associated with parent-assessed well-being, and (3) has a stronger negative association with self-assessed well-being for girls compared to boys.

Altruism depends on the source of one’s wealth: in the lab, participants give much less when an endowment is earned than when it comes as a windfall. In reality, however, there exists much uncertainty about the relative importance of effort and luck in determining income and wealth. In three experiments, I investigate altruism under endowment-source uncertainty. I find evidence that participants use different allocation rules under certainty and uncertainty, consistent with models of limited or costly cognition.

HM Treasury’s estimation of the economic consequences of Brexit – using standard macroeconomic models – during the EU referendum campaign represents a remarkable intervention in a highly politicized public debate. It raises a series of questions about the use of economic expertise. Through a detailed theoretical and empirical critique of the Treasury’s methodology – and a reassessment of the likely effects of Brexit in light of this – we cast doubt on the utility of their approach, highlighting methodological issues, unrealistic assumptions, and misrepresentations of established facts. In the process we seek to identify some of the wider implications for the use and potential abuse of economic expertise in highly charged political contexts, such as the EU referendum debate.

A basic but as yet unachieved goal for UN missions is to know the exact locations of their peacekeepers at any given time. Such tracking would help field missions plan operations, avoid and respond to ambushes, kidnappings and friendly fire incidents, rapidly send reinforcements and retrieve wounded peacekeepers, ultimately saving lives. Improved effectiveness could be obtained from ‘precision peacekeeping’, where soldiers, police and civilians are deployed to precise locations and events, while operational leaders follow their movements. Fortunately, tracking technology has improved considerably so that commercial solutions for real-time tracking of personnel and vehicles are now available at lower cost and increased accuracy and sophistication, while being more user-friendly. The advances in phone and vehicle tracking systems are reviewed here to identify the benefits, drawbacks and challenges, especially any political ones, for the United Nations. The world organization can benefit from modern blue mission tracking, without having to develop costly, customized solutions. Such initiatives have few technological or financial hurdles but the politics and institutionalization of continuous positional surveillance needs policy modernization, guided by a nuanced understanding of technological empowerment.