recent years, but they do not suffer from the aforementioned limitations of the DMSP-OLS data.<sup>4</sup> They are furthermore available at more granular time scales (i.e., monthly composites), making them better suited for detecting variation in economic activity at the city level over shorter periods of time (Gibson et al., 2021; Roberts, 2021).<sup>5</sup> Finally, this study also contributes to an emerging literature on the economic impacts of pandemics, galvanized by the onset of the Covid-19 crisis. <mark>Miguel and Mobarak (2022) provide a survey of the rapidly growing empirical research documenting the current pandemic's many adverse impacts on living standards, human capital, and inequality in low- and middle-income countries.</mark> Many studies have also focused on the medium- to long-run economic impacts of historic pandemics, often focusing on the redistributive impacts across labor and capital (Almond, 2006; Alfani, 2022; Jedwab et al., 2021; Jedwab et al., 2022; Jordà et al., 2022). To the best of our knowledge, our study is the first to examine the more immediate, short-run response of city trajectories to the outbreak, and how these vary across cities, at a global scale. In doing so, it builds on country-specific applications of nighttime lights data to study the economic impacts of the Covid-19 crisis for China (Elvidge et al., 2020; Liu et al., 2020), India (Beyer et al., 2021), and Morocco (Roberts, 2021). It also contributes to the debate on the efficacy of NPIs in containing the negative health and economic impacts of pandemics (Correia et al., 2020; Demirguc-Kunt et al., 2020; Barro, 2020). The evidence from our analysis suggests that, in terms of economic activity, the negative impacts of Covid-19-induced deaths outweigh the costs of NPIs.<sup>6</sup> The next section of the paper, Section 2, introduces the data used and presents some descriptive statistics regarding the evolution of lights following the emergence of Covid-19. Section 3 then investigates the determinants of the local economic impacts of the Covid-19 pandemic using three empirical approaches – a panel data approach that exploits both cross-country and temporal variation in Covid-19 deaths and the stringency of NPIs; a cross-sectional approach that estimates the strength of the correlation between various city-level characteristics, including density, and deviations in nighttime light intensity from a city’s own pre-Covid-19 growth path following the onset of the crisis; and an event study approach that examines impacts on more versus less densely populated cities. Section 4 concludes.

# **2. Data Description**

This study combines various spatial data sets to measure aggregate economic activity in cities, the progress of Covid-19, the policy measures implemented in response, and cities’ socio-economic characteristics. The primary data is VIIRS DNB monthly composites obtained from the Earth Observation Group (EOG) at the Colorado School of Mines. This data covers the period from April 2012 through March 2021. Each monthly data point represents a pixel’s average nighttime light intensity over all cloud-free nights in that month measured in nanowatts/cm<sup>2</sup> /sr. For each month, we proxy a city’s overall level of economic activity by its “sum of lights” (SOL) – i.e., by the sum of the nighttime light intensities across all 15 arc-second (approximately 460 m<sup>2</sup> at the equator) pixels that fall within a city’s extent. For global consistency, we use data on “urban centers” from the Global

> 4 While overglow still occurs in the VIIRS data, it is a much less severe problem than for the DMSP-OLS data (Small, 2019).

> 5 Other studies have exploited alternative proxies for economic activity derived from credit card transactions and private sector payroll firms (Chetty et al., 2020), Google Trends search data (Woloszko, 2020), and data on outdoor air pollution levels (Masaki et al., 2020).

> 6 Given that, for any given month, the VIIRS nighttime lights composite becomes available within a few weeks of the month’s end under the Colorado School of Mines’ Earth Observation Group (EOG) subscription service, the use of nighttime lights also has potential to contribute to the “near real-time” monitoring of economic activity in response to shocks.

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