We propose a dynamic general equilibrium model of exchange rate determination that accounts for all major exchange rate puzzles, including Meese-Rogoff, Backus-Smith, purchasing power parity, and uncovered interest rate parity puzzles. We build on a standard international real business cycle model with home bias in consumption, augmented with shocks in the financial market that result in a volatile near-martingale behavior of exchange rates and ensure their empirically relevant comovement with macroeconomic variables, both nominal and real. Combining financial shocks with conventional productivity and monetary shocks allows the model to reproduce the exchange rate disconnect properties without compromising the fit of the business cycle moments.

Large firms play a pivotal role in international trade. We develop a multisector granular model of trade where sectors host a finite number of firms. Both aggregate and granular firm-level forces shape comparative advantage. The model is estimated using French microdata on firm domestic and export sales. We find that granularity accounts for about 20% of the sectoral variation in export intensity and is more pronounced in highly export-intensive sectors. An extension to a dynamic environment with both idiosyncratic and aggregate shocks reveals that firm dynamics plays a central role in shaping comparative advantage reversals observed in the data.