Chapter 1 highlights a source of financial frictions associated with intangible assets. I construct new measures of firm-level intangible and physical assets using accounting information on U.S. public firms. I find that firms with a higher initial share of intangible assets (i) start smaller, (ii) grow faster, and (iii) have higher market value per unit of total assets. Intangible share predicts firm dynamics for up to 40 years but its predictive power diminishes over time. I develop a model with heterogeneous firms and financial frictions in which firm size and growth are limited by the enforceability of financial contracts. The share of intangible assets matters because physical and intangible assets differ in their residual value for th...