This dissertation consists of two chapters on topics in innovation. The first chapter analyzes how alternative patent enforcement regimes affect inventors in the market. How does a change in enforcement costs influence the inventors\u27 decisions to keep, sell to an intermediary, or enforce their patents through litigation? How much do inventors earn out of patent enforcement and trade under alternative cost structures? I combine publicly available litigation data with data on intermediaries to (i) document the impact of having tougher standards on the preliminary injunction on patent sale prices and incentives, (ii) calibrate a dynamic game, (iii) simulate counter-factual outcomes under different patent enforcement systems to quantify bene...