Too Hot to Succeed? Heat Waves, Exam Performance, and Noisy Signals in College Admissions

Climate change is increasing students’ exposure to extreme heat. Moreover, these extreme temperatures are likely to become frequent in June, a period over which the French end-of-high-school exam (Baccalauréat) takes place. Studies in China and the United States show that a one standard deviation increase in temperature (around 2°C) during exams lowers test scores by about 5 to 6% of a standard deviation. We ask whether heat on the exam day lowers students’ achievement in France and, more importantly, whether this impacts who gets admitted to which higher education programme, as well as academic success in post-secondary education.

France is a particularly well-suited setting. High schools are barely ever air-conditioned and buildings tend to be old, making room temperature close to outdoor temperature. We will leverage the timing of the written French exam, typically taking place around June 15th at the end of grade 11, to assess the impact of heat waves on student admissions into post-secondary education, acknowledging this exam is an important part of applications files on Parcoursup (the centralised platform for admission to higher education). We will also leverage spatial differences in chronic high-temperature exposure to estimate the long-term effect of a hotter climate.

To measure exposure, we built a panel linking every high-school to Météo-France’s SAFRAN grid (8 km, daily since 1958, hourly-interpolation on exam days). This lets us measure temperature and humid heat during the actual exam hours, and to distinguish heat during the exam from heat during the night before.