International trade and macroeconomic dynamics with sanctions

We develop a framework combining dynamic, intertemporal choices of general-equilibrium macro models with microfoundations of modern trade theory to study sanctions. In a two-country, two-sector setup, Home holds a comparative advantage in producing differentiated consumption goods via heterogeneous firms with endogenous entry, while Foreign in homogeneous intermediate goods from a fixed number of firms. Sanctions include trade bans and financial restrictions excluding particular Foreign agents from markets. In our model, sanctions reallocate resources across and within countries, affecting production, exchange rates, and welfare, with larger welfare losses when targeting sectors of comparative disadvantage. Focusing only on long-run outcomes, overlooking initial dynamics, inaccurately assesses welfare impacts. Sanctions weaken international comovement and fragment markets but leave business cycles intact.