2 find that relationships between mortality rates up to December 2020 and age have an exponential relationship with age. Thus, while many prime-aged workers died from COVID, their impact on the global stock of human capital is likely small. More broadly, given that the U.S. was one of the worst affected countries in the world by COVID-19, it is reasonable to extrapolate that few parts of the world are likely to experience as severe a human capital loss from COVID-19 through the mortality channel.

Finally, while Demombynes (2020) and Demombynes et al. (2021) show using official and excess deaths data from 26 and 64 countries that age-mortality curves for 2020 were flatter in developing countries than in developed countries, their Figure 4 confirms that COVID-19 mortality rates were relatively low below age 60 in most countries.

# **C Calibration: Defining the Pandemic: Schooling Shock**

**College Shock & Effectiveness of Online College.** We assume that the returns to college  ̄ _rs_ are not disrupted. This is because the evidence so far on COVID-19 does not suggest significant disruption to college enrollment numbers – and, while this may not have been the case for past pandemics, technological advances suggest that the COVID19 pandemic is a good benchmark looking forward.<sup>3</sup> Additionally, the literature on the effectiveness of online college is mixed. Some studies find that online education can be effective (sometimes more effective than in-person education – see Jaggars and Bailey (2010)) while others suggest it is not, e.g. Alpert et al. (2016) and Bettinger et al. (2017). Selection effects may cloud the results (Xu and Jaggars, 2013). A few studies on online education during the pandemic find that it was sometimes less effective than in-person instruction (Donnelly and Patrinos, 2021), but the effect is not large – e.g. Kofoed et al. (2021) find that online instruction lowered average grades by one half of a grade step (e.g. the difference between a B and a B+). Given this lack of decisive evidence either way, we make a conservative assumption that college is unaffected. Note that assuming that college returns are also lowered during the pandemic will only exacerbate the finding that HICs are more affected through learning losses than MICs and LICs.

**Effectiveness of Online Primary and Secondary Schooling.** The literature provides mixed results. In a panel of Dutch schools, Engzell et al. (2021) find that the learning loss during 5 months of online and hybrid schooling was equivalent to 5 months of schooling loss, suggesting that online instruction is entirely ineffective. Maldonado and De Witte (2021) for the case of Flanders find that students’ exam performance is consistent with having gained only between a half and a quarter of what was expected in terms of knowledge, indicating that effectiveness e=1 is not realistic. On the other hand,

3 Based on National Student Clearinghouse data, undergraduate enrollment was down 3 _._ 5 percent in the U.S. from Spring 2019 to Spring 2020. This was offset by an increase in graduate enrollments of 4 _._ 6 percent. See https://nscresearchcenter.org/current-term-enrollment-estimates/, last checked 10/1/21.