This paper studies how distortions alter decisions of firms in producing multiple products (MP). Using the Annual Survey of Industrial Firm data in China, we find (i) multi-product firms are fewer and smaller than in the U.S.; (ii) the MP probability of a firm is negatively associated with the...

We present a multi-city economic model to study the endogenous choice of migration and to evaluate various policy alternatives during a pandemic. We combine a traditional epidemic dynamic model with endogenous migration decisions between cities and provide analytical solutions under two...

We present a multi-city migration model to study the endogenous choices of migration during a pandemic and to evaluate various policy alternatives as well. Analytical solutions are provided under the two situations respectively: laissez-faire equilibrium and social optimum. We find that...