Department of Economics2024-11-1019993-540-65383-XN/Ahttps://hdl.handle.net/20.500.14288/17214We examine the impact of learning about the unknown costs of investment on irreversible investment decisions, and show that the presence of:learning increases the endogenous cost of adjustment and depresses investment. We demonstrate convergence of the state of information and capital stock to the ergodic set. Once learning is complete, in-contrast to the exogenous cost-of-adjustment model, a mean-preserving increase in risk raises the endogenous marginal adjustment cost, reducing investment and the steady-state capital stock. We use data on the U.S. economy to study the impact of uncertainty and risk in the determinants of the costs of investing. Among our Salient findings is that increases in uncertainty have a much larger impact quantitatively on investment than increases in risk. Thus, if firms are unsure about various aspects of the stochastic environment that they face, the reduction in investment is much larger compared to the case in which there are increases in the riskiness in the price of capital or Other determinants of the costs of investing.EconomicsConference proceeding85756700004256