The supply and demand of credit are not always well aligned and matched, as is reflected in the countercyclical excess reserve-to-deposit ratio and interest spread between the lending rate and the deposit rate. We develop a search-based theory of credit allocations to explain the cyclical fluctuations in both bank reserves and the interest spread. We show that search frictions in the credit market can not only naturally explain the countercyclical bank reserves and interest spread, but also generate endogenous business cycles driven primarily by the cyclical utilization rate of credit resources, as long conjectured by the Austrian school of the business cycle. In particular, we show that credit search can lead to endogenous local increasing returns to scale and variable capital utilization in a model with constant returns to scale production technology and matching functions, thus providing a micro-foundation for the indeterminacy literature of Benhabib and Farmer (1994) and Wen (1998).