We study business cycles with cyclical returns to scale. Contrary to tightly parameterized production functions (Cobb-Douglas and Constant Elasticity of Substitution), we empirically identify strong input complementarity that leads to procyclical returns to scale. We therefore propose a flexible...

How are a firm's size and market power related to one another? Combining micro-data about producers and consumers, we document that while firms mainly grow by selling to more customers, their markups are only associated with their average sales per customer. To study the macroeconomic...