We measure trends in affective polarization in nine OECD countries over the past four decades. The US experienced the largest increase in polarization over this period. Three countries experienced a smaller increase in polarization. Five countries experienced a decrease in polarization. These...

We combine nine previously proposed measures to construct an index of political polarization among US adults. We find that the growth in polarization in recent years is largest for the demographic groups least likely to use the internet and social media. For example, our overall index and eight...

We provide new evidence on the drivers of the early US coronavirus pandemic. We combine an epidemiological model of disease transmission with quasi-random variation arising from the timing of stay-at-home-orders to estimate the causal roles of policy interventions and voluntary social...

We document trends in affective polarization during the coronavirus pandemic. In our main measure, affective polarization is relatively flat between July 2019 and February 2020, then falls significantly around the onset of the pandemic. Two other data sources show no evidence of an increase in...

We study partisan differences in Americans' response to the COVID-19 pandemic. Political leaders and media outlets on the right and left have sent divergent messages about the severity of the crisis, which could impact the extent to which Republicans and Democrats engage in social distancing and...