Although firms may face radically different production conditions, this dimension of firm heterogeneity is often overlooked. We model input demand across local factor markets, explicitly considering search costs which explain why firms care about both the price and availability of inputs. The...

A fundamental question in monopolistic competition theory is whether the market allocates resources efficiently. This paper generalizes the Spence-Dixit-Stiglitz framework to heterogeneous firms, addressing when the market provides optimal quantities, variety and productivity. Under constant...

Which products are potentially produced together? When demand for a product increases, which firms will supply it? Using multi-product production patterns within and across firms, we recover a continuous cost-based distance between firms and unproduced products. Higher product distance implies...