This paper builds a theory of the shape of the distribution of total-factor productivity (TFP) across countries. The data on productivity suggests vast differences across countries, and arguably even has "twin peaks". The theory proposed here is consistent with vast differences in long-run...

We use an analytically tractable heterogeneous-agent (HANK) version of the standard New Keynesian model to show how the size of fiscal multipliers depends on (i) the distribution of factor incomes, and (ii) the source of nominal rigidities. With sticky prices but flexible wages, the standard...

We construct an integrated assessment model with multiple energy sources - two fossil fuels and "green energy" - and use it to evaluate ranges of plausible estimates for the climate sensitivity as well as for the sensitivity of the economy to climate change. Rather than focusing on uncertainty...

How do markets economize on scarce natural resources? With an application to fossil energy, we emphasize technological change aimed at saving on the scarce resource. We develop quantitative macroeconomic theory as a tool for interpreting the past and thinking about the future. We argue, first,...