OECD governments have responded at unprecedented scale and speed to the COVID-19 crisis. The pandemic, and the economic and social effects of the measures to contain it, are the largest shock most OECD countries have experienced since the Second World War. They have been required to implement policy and operational responses of unprecedented scale, speed and scope to contain the pandemic. Health care systems have had to be extensively scaled up to treat the ill. Efforts to slow transmission rates have required restrictions on civic freedoms and economic activities on a scale rarely seen in democratic states in peacetime. The restrictions on economic activity have generated major disruption to incomes and employment, requiring governments to provide massive fiscal support for citizens and businesses.