Essays on market frictions, economic shocks, and business fluctuations

My dissertation investigates what types of shocks cause business fluctuations and what roles the frictions existing in an economy are playing in propagating the shocks. Specifically, I focus on the propagation mechanism of the shocks to (i) agents' expectation and (ii) frictions or uncertainty in financial or goods markets, all of which have gradually been the center of attention in the recent business cycle literature.;In the first essay, "Financial Frictions, Intersectoral Adjustment Costs, and News-Driven Business Cycles", I show that an RBC model with financial frictions and intersectoral adjustment costs can generate sizable boom-bust cycles and plausible responses of stock prices in response to a news shock. Booms in the labor market, which make it possible for both consumption and investment to increase in response to positive news, are caused through two channels: the increases in value of marginal product of labor and the increases in value of collateral. Both of these channels enable firms to hire more workers. Intersectoral adjustment costs contribute to both channels by increasing the relative price of output and capital during expansions. Financial frictions enter in the forms of collateral constraints on firms, which influence the latter channel, and the financial accelerator mechanism driven by agency costs, which amplifies all the key variables. My model differs from previous studies in its ability to generate boom-bust cycles without restricting the functional form of consumption in household preferences and without requiring investment adjustment costs, variable capital utilization, or any nominal rigidities.;In the second essay, "Financial and Real Frictions as Sources of Business Fluctuations", I show that a negative shock to a financial or real friction in an economy can generate quantitatively significant and persistent recessions, even without a decrease in exogenous aggregate total factor productivity in a heterogeneous agents DSGE model. The increase in uncertainty that a firm is facing when it makes capital adjustment, however, is found to have a limited or dubious in influence on economic activities. The roles of collateral constaints as a financial friction and nonconvex capital adjustment costs as a real friction in aggregate fluctuations are examined in this propagation mechanism. When these frictions become strengthened, the degree of capital misallocation is intensified, which leads to a drop of endogenous aggregate total factor productivity. As agents expect that the return to investment and endogenous TFP decrease, they reduce aggregate investment sharply, which also leads to a drop in employment. Interruption of efficient resource allocation coming from these two frictions is found out to be enough to generate a large and persistent aggregate fluctuations even without introducing heterogeneity in firm-level productivity.