_4_ They find that hotter years are associated with lower or higher output per capita ranging between 3 and 4 percent for hot or cold climate zones, respectively. In most cases, labor productivity may be the key link between climate shocks and economic outcomes at the macro level (Heal and Park, 2013). Yet, there are few studies on the direct links between labor productivity and temperature changes. Tol (2009) labels the labor productivity impacts of climate change as _unknown unknowns_ in a review of studies on the economic effects of climate change, noting the wide gap in the literature, although there has been significant progress since then.

More recent studies have examined the impacts of rising temperatures on various aspects of labor productivity at the micro level (see Lai et al. (2023) for a review). However, many such studies provide average estimates of the impact of climate change or temperature deviations from the average, without accounting for the potentially uneven impacts across climate zones, regions, or countries. Neglecting the uneven impacts will have significant implications for understanding how climate change shapes the future distribution of economic outcomes across these categories. Using detailed production data from half a million manufacturing firms in China, Zou and Zhong (2022) find a relatively large negative impact of excess temperatures—a day with average temperature above 90 degrees Fahrenheit (<sup>0</sup> F) is associated with a total factor productivity (TFP) loss of 0.56 percent, relative to a day with average temperature between 50<sup>0</sup> F and 60<sup>0</sup> F. A study of a census of manufacturing firms in India shows that annual plant output falls by about 2 percent per 1<sup>0</sup> C increase in temperature (Somanathan et al., 2021). In a U.S. study, Deryugina and Hsiang (2014) show that productivity on an individual day declines by 1.7 percent for each 1<sup>0</sup> C (1 _._ 8<sup>0</sup> F) increase in daily average temperature above 15<sup>0</sup> C (59<sup>0</sup> F). Many of these studies that examine the productivity impacts of temperature focus on a few individual countries, hence providing only limited variations in terms of both the impact of temperature changes on productivity and variations across countries by income and geography.

LoPalo (2023) addresses this challenge in an innovative study that extends the analysis to 46 countries, examining the effects of WBT on the productivity of Demographic and Health Survey interviewers. She finds that hot and humid temperatures significantly impact worker productivity. Data quality problems, such as missing responses and flags for poor data quality, become more frequent on hotter days and interviewers become less productive. The number of interviews completed per hour worked declines by 13.6 percent on the hottest days. However, interviews and data collection make up a unique context. LoPalo (2023) provides interesting evidence on the link between temperature and survey workers’ productivity from a broad set of countries and regions, allowing for heterogeneous impacts across countries. However, the findings cannot be generalized to enterprises since data collection is a small share of economic activity, and the usually