One of the perceived advantages of difference-in-differences (DiD) methods is that they do not explicitly restrict how units select into treatment. However, when justifying DiD, researchers often argue that the treatment is "quasi-randomly" assigned. We investigate what selection mechanisms are...

Countries have employed a variety of non-pharmaceutical interventions (NPIs) in order to curtail the Covid-19 pandemic. However, the success of individual measures in reducing the number of infections remains controversial. This paper exploits a panel data set of 182 countries to estimate the...

Decisions on public health measures to contain a pandemic are often based on parameters such as expected disease burden and additional mortality due to the pandemic. Both pandemics and non-pharmaceutical interventions to fight pandemics, however, produce economic, social, and medical costs. The...

We develop a multiple-events model and exploit within and between country variation in the timing, type and level of intensity of various non-pharmaceutical interventions to study their dynamic effects on the daily incidence of COVID-19 and on population mobility patterns across 135 countries....

Early non-pharmaceutical interventions (NPI) significantly reduced the death toll of the Covid-19 pandemic. Yet, there are vast differences in how quickly governments implemented NPIs. In this paper, we analyze the role of public attention, measured as the share of daily Google searches in a...

This study documents how the demographics of new infections and mortality changed over time across US counties. We find that counties with a larger population share aged above 60 were hit harder initially in terms of both cases and mortality in March and April while counties with a larger...

Empirical work described in this paper explains the daily evolution of the reproduction rate, R, and mobility for a large sample of countries, in terms of containment and public health policies. This is with a view to providing insight into the appropriate policy stance as countries prepare for...

The COVID-19 pandemic has brought into sharp relief the connection between the epidemiology of a virus, the structure of the economy and society that becomes exposed to it, and the actions chosen by government and by individuals and communities to combat it or ameliorate its economic impact....

We use the US presidential election on 3 November 2020 to examine how the US president influences economic expectations of international experts. We design a large-scale RCT among 843 experts working in 107 countries, asking about their expectations regarding GDP growth, unemployment, inflation,...

Understanding the mechanisms through which treatment effects come about is crucial for designing effective interventions. The identification of such causal mechanisms is challenging and typically requires strong assumptions. This paper discusses identification and estimation of natural direct...