Publications and accepted papers
Temperature variability and long-run economic development
Published in: Journal of Environmental Economics and Management, 2023
This study examines the effects of temperature variability on long-run economic development. To identify causal effects, a novel econometric strategy is employed, based on spatial first-differences. Economic activity is proxied by satellite data on nightlights. Drawing on climate science, the study distinguishes between temperature variability on three time scales: day-to-day, seasonal, and interannual variability. The results indicate that day-to-day temperature variability has a statistically significant, negative effect on economic activity, while seasonal variability has a smaller but also negative effect. The effect of interannual variability is positive at low temperatures, but negative at high temperatures. Furthermore, the results suggest that daily temperature levels have a non-linear effect on economic activity with an optimal temperature around 15 degrees Celsius. However, most of the estimated effects of variability cannot be explained with this non-linearity and instead seem to be due to larger uncertainty about future temperature realisations. The empirical effects can be found in both urban and rural areas, and they cannot be explained by the distribution of agriculture. The results indicate that projected changes of temperature variability might add to the costs of anthropogenic climate change especially in relatively warm and currently relatively poor regions.
Global benefits of the international diffusion of carbon pricing policies
with Adil Mohommad and Gregor Schwerhoff
Published in: Nature Climate Change, 2023
In this paper, we study the international diffusion of carbon pricing policies. In the first part, we empirically examine to what extent the adoption of carbon pricing in a given country can explain the subsequent adoption of the same policy in other countries. In the second part, we quantify the global benefits of policy diffusion in terms of greenhouse gas emission reductions elsewhere. To do so, we combine a large international dataset on carbon pricing with several other datasets. For causal identification, we estimate semi-parametric Cox proportional hazard models. We find robust and statistically significant evidence for policy diffusion. The magnitude of the estimated effects is substantial. For two neighbouring countries, policy adoption in one country increases the probability of subsequent adoption in the other country on average by several percentage points. Motivated by this result, we use Monte Carlo simulations based on our empirical estimates to quantify both direct domestic and indirect foreign emission reductions of policy adoption and subsequent diffusion. The results based on our central empirical estimates suggest that for most countries indirect emission reductions of carbon pricing can exceed direct emission reductions. Overall, our results provide additional support for the adoption of stringent climate policies, especially in countries where climate change mitigation policies might so far have been considered as being of relatively little importance because of a relatively small domestic economy.
Weather drives variation in COVID-19 transmission and detection
with Ana De Menezes-Silva and James Rising
Published in: Environmental Research: Climate, 2023
The debate over the influence of weather on COVID-19 epidemiological dynamics remains unsettled as multiple factors are conflated, including viral biology, transmission through social interaction, and the probability of disease detection. Here we disentangle these dynamics with a multi-method approach combining econometric techniques with epidemiological models to analyze data for over 4000 geographic units. We show distinct and significant effects of temperature, thermal comfort, solar radiation, and precipitation on the growth of infections. We find that weather affects the rates of both disease transmission and detection, and we isolate transmission effects to understand the potential for seasonal shifts. The instantaneous effects of weather are small, with R0 about 0.007 higher in winter than summer. However, these effects compound over time, so that a region with a 5 C drop over three months in winter is expected to have 190% more confirmed cases at the end of that 90 days period, relative to constant temperature. We also find that the contribution of weather produces the largest effects in high-latitude countries. As the COVID-19 pandemic continues to evolve and risks becoming endemic, these seasonal dynamics may play a crucial role for health policy.
Policy sequencing towards carbon pricing among the world’s largest emitters
with Adil Mohommad and Gregor Schwerhoff
Published in: Nature Climate Change, 2022
Carbon pricing is considered the most efficient policy to reduce greenhouse gas emissions but it has also been conjectured that other policies need to be implemented first to remove certain economic and political barriers to stringent climate policy. Here, we examine empirical evidence on the the sequence of policy adoption and climate policy portfolios of G20 economies and other major emitters that eventually implemented a national carbon price. We find that all countries adopted carbon pricing late in their instrument sequence after the adoption of (almost) all other instrument types. Furthermore, we find that countries that adopted carbon pricing in a given year had significantly larger climate policy portfolios than those that did not. In the last part of the paper, we examine heterogeneity among countries that eventually adopted a carbon price. We find large variation in the size of policy portfolios of adopters of carbon pricing, with more recent adopters appearing to have introduced carbon pricing with smaller portfolios. Furthermore, countries that adopted carbon pricing with larger policy portfolios tended to implement a higher carbon price. Overall, our results thus suggest that policy sequencing played an important role in climate policy, specifically the adoption of carbon pricing over the last two decades.