Socially optimal search intensity in over-the-counter markets

This paper investigates the endogenous search intensity of traders in the OTC market, examining both competitive equilibrium and socially optimal scenario. Our study introduces a random search-and-matching model, where traders have the flexibility to ex post choose and adjust their search intensities based on two trader-level states: asset position and preference type. Our findings uncover the following key insights: (1) Changes in the level of search friction and/or the frequency of shocks on traders' preference type may lead to traders switching between high and low search intensities, shifting between the core and periphery of the trading network; and (2) Social optimality is achieved in the absence of intermediation, where no trader simultaneously invests in positive buying intensity and positive selling intensity. In contrast, competitive equilibrium reveals that some traders tend to over-search while others under-search, compared to the socially optimal outcome.