Using rapid expansion of the Beijing subway from 2000 to 2018, we analyze its impact on collaborative matches in innovations. We find that an hour reduction in travel time between a pair of locations in Beijing brought 14.85% to 37.69% increase in collaborated patents. Far-apart location pairs were more affected, and the local average causal response is approximately 34.92% to 82.29%. The effect is mainly driven by increased matches among highly productive innovators. The entry of new innovators, relocation of existing innovators, and collaborations among low-productive innovators also contribute to the increase in collaborative matches, especially in the long run.

Using over 11,000 unlicensed loans to over 1,000 borrowers in Singapore, we provide basic information about an understudied market: illegal moneylending. Borrowers and lenders interact frequently and rely primarily on relational contracts to enforce their agreements. Borrowers have high discount rates, often have gambling and/or substance abuse problems, and often repay late. While lenders sometimes resort to nonfinancial punishments, the primary cost of late repayment is the compounding of a very high interest rate. Consistent with our view that lenders cannot extract all surplus, a crackdown on illegal lending raised interest rates and lowered the size of loans.