Trade policy is often cast as a solution to the free‐riding problem in international climate agreements. This paper examines the extent to which trade policy can deliver on this promise. We incorporate global supply chains of carbon and climate externalities into a multi‐country, multi‐industry general equilibrium trade model. By deriving theoretical formulas for optimal carbon and border taxes, we quantify the maximum efficacy of two trade policy solutions to the free‐riding problem. Adding optimal carbon border taxes to existing tariffs proves largely ineffective, delivering only 3.4% of what could be achieved under globally optimal carbon pricing. In contrast, Nordhaus's (2015) climate club framework, in which border taxes are used as contingent penalties to deter free‐riding, can achieve 33–68% of the globally optimal carbon reduction, depending on the initial coalition (EU, EU + US, or EU + US + China). In all cases, the climate club ensures universal compliance, thereby preserving free trade.

We predict and confirm that long-term institutional investors (LTIOs) play an important role in mitigating the negative market perceptions of US stocks following mainstream print media coverage of climate change. We observe a stronger effect of LTIOs for companies that lack corporate social responsibility and have less diverse and more co-opted boards. Overall, these findings indicate that the US equity market views LTIOs as effective monitors who can help guide companies facing climate risks toward a more sustainable trajectory.

We match firm-corporate governance characteristics with firm-level carbon dioxide (CO2) emissions over the period 2009–2019 to study the relationship between gender diversity in the workplace and firm carbon emissions. We find that a 1 percentage point increase in the percentage of female managers within the firm leads to a 0.5% decrease in CO2 emissions. We document that this effect is statistically significant, also when controlling for institutional differences caused by more patriarchal and hierarchical cultures and religions. At the same time, we show that gender diversity at the managerial level has stronger mitigating effects on climate change if females are also well-represented outside the organization, e.g. in political institutions and civil society organizations. Finally, we find that, after the Paris Agreement, firms with greater gender diversity reduced their CO2 emissions by about 5% more than firms with more male managers.

Employing droughts and floods to proxy for changes in precipitation, this paper shows nomadic incursions into settled Han Chinese regions over a period of more than two thousand years—the most enduring clash of civilizations in history—to be positively correlated with less rainfall and negatively correlated with more rainfall. Consistent with findings that economic shocks are positively correlated with conflicts in modern sub-Saharan Africa when instrumented by rainfall, our reduced-form results extend this relationship to a very different temporal and geographical context, the Asian continent, and long historical period.

We examine the structure of preferences for mitigating impacts of global climate change that will not occur during the lifetimes of most who are alive today. Because no market data exist for such distant markets, a statedpreference approach is used. The analysis is based on the random-parameters logit model, and the results indicate substantial heterogeneity in respondent preferences, that mean willingness to pay is a significant and increasing function of the scope of the impact, and, provocatively, that respondents have the same preferences over the two very different time horizons that we consider.

Research finds that climate disasters have had minimal effects on banks’ performance to date, and it has devoted limited attention to how banks shape societal exposure to the disasters. This study addresses this puzzle and gap. Examining the share price reactions of banks affected by billion-dollar disasters from 1994–2024, we find that on average these banks lost market value around the disasters exceeding 10 percent of the estimated damages, with this percentage more than doubling during the sample period. We next show that banks’ county-level mortgage lending is positively associated with property exposures to disasters and FEMA appropriations when disasters occur. Finally, we show that banks open new branches in counties that experience growth in socially advantaged population, especially counties with high climate risks. Given accelerating climate change, property-casualty insurers backing away from climate-risky counties, and FEMA’s uncertain status, our evidence highlights growing climate-related costs for banks and society.

U sing lenders who become members of the Task Force on Climate-Related Financial Disclosures (TCFD) as an exogenous shock, we examine whether and how lenders’ commitment to transparent climate-related disclosures affects borrowers’ environmental performance. We find that borrowers of TCFD-member lenders, relative to control firms, significantly improve their environmental performance after the TCFD launch. Lenders’ disclosure commitments influence borrowers through credit rationing and monitoring. Specifically, polluting borrowers face higher borrowing costs, reduced access to credit, and greater incorporation of environmental action covenants in loan agreements. Additionally, polluting borrowers of TCFD-member lenders experience heightened financial constraints. Finally, borrowers of TCFD-member lenders are more likely to adopt the TCFD framework for climate-related disclosure after the TCFD establishment. Together, these findings illuminate the role of lenders in driving corporate environmental performance improvement through their commitment to transparent climate-related disclosures.

We consider the effects of climate change on seasonally migrant populations that herd livestock—i.e. transhumant pastoralists—in Africa. Traditionally, transhumant pastoralists benefit from a cooperative relationship with sedentary agriculturalists whereby arable land is used for crop farming in the wet season and animal grazing in the dry season. Rainfall scarcity can disrupt this arrangement by inducing pastoral groups to migrate to agricultural lands before the harvest, causing conflict to emerge. We examine this hypothesis by combining ethnographic information on the traditional locations of transhumant pastoralists and sedentary agriculturalists with high-resolution data on the location and timing of rainfall and violent conflict events in Africa from 1989 to 2018. We find that reduced rainfall in the territory of transhumant pastoralists leads to conflict in neighbouring areas. Consistent with the proposed mechanism, the conflicts are concentrated in agricultural areas; they occur during the wet season and not the dry season; and they are due to rainfall’s impact on plant biomass growth. Since pastoralists tend to be Muslim and agriculturalists Christian, this mechanism accounts for a sizable proportion of the rapid rise in religious conflict observed in recent decades. Regarding policy responses, we find that development aid projects tend not to mitigate the effects that we document. By contrast, the effects are reduced when transhumant pastoralists have greater power in national government, suggesting that more equal political representation is conducive to peace.

The latitude gradient in comparative development is a striking fact: as one moves away from the equator, economic activity rises. While this regularity is well known, it is not well understood. In the present paper we take a step towards unpacking this gradient. Perhaps the strongest correlate with (absolute) latitude is the intensity of ultraviolet radiation (UV-R), which epidemiological research has shown to be a cause of a wide range of diseases. We establish that UV-R is strongly and negatively correlated with economic activity, both across and within countries. We propose, and test, a mechanism that links UV-R to current income differences via the impact of disease ecology on the timing of the take-off to sustained growth.