We consider a two-sided, finite-horizon search and matching model with heterogeneous types and complementarity between types. The quality of the pool of potential partners deteriorates as agents who have found mutually agreeable matches exit the market. When search is costless and all agents participate in each matching round, the market performs a sorting function in that high types of agents have multiple chances to match with their peers. However, this sorting function is lost if agents incur an arbitrarily small cost in order to participate in each round. With a sufficiently rich type space, the market unravels as almost all agents rush to participate in the first round and match and exit with anyone they meet.

We investigate how differences in regulation regarding banking-commerce integration and banking sector concentration influence loan spreads across 29 countries. Theoretical research posits conflicting effects based on agency costs, information asymmetry costs, and market power. Increased integration is associated with lower loan spreads in countries with low concentration, but moving to high levels of integration increases spreads in countries with high concentration. Starting from lower levels, an increase in integration is associated with an increase in informational efficiency that disappears at higher levels of integration. We also show that market concentration affects loan spreads differently under high-, medium-, and low-integration regimes.

We propose a novel high-frequency decomposition of daily stock returns into news- and non-news-driven components, and uncover evidence of pervasive stock market underreaction to firm news. Prices tend to drift in the same direction as the initial market response for several days after the news arrival without reversals. A trading strategy exploiting the return drift generates high abnormal returns and remains profitable after transaction costs. To understand the economic mechanism, we find that the return drift is stronger when investors are distracted. Analysts’ slow adjustments of market expectations following firm news also contribute to the market underreaction.