Much of the recent work in financial economics can be viewed as an attempt to synthesize contemporary financial market theory with the theory of the firm under uncertainty. This line of research analyzes firm behavior using models that explicitly incorporate the capital market's valuation of risk. The early results indicate that this basic approach holds great promise in its ability to consider the financial market effects on a host of decisions made at the firm level. In this paper we extend the recent work of Greenberg et al. and Shrieves on the choice of input mix under uncertainty. In particular, we demonstrate that the qualitative nature of the disturbance term, along with the decision sequence, is a crucial determinant of the overall effect of uncertainty on the optimal input mix of a firm. Using general demand and production functions in conjunction with a mean-variance framework for financial valuation, we demonstrate the differential effects of systematic and nonsystematic risk on the firm's choice of an optimal input mix. Consistent with earlier work in economics, this analysis demonstrates that uncertainty, regardless of the source, has important implications for the firm's choice of technology. When the source of the uncertainty is firm-specific, there is no need to take account of any reaction in the capital markets; the risk-free rate of interest is the only relevant financial market variable. We refer to the relationship between this type of uncertainty and the choice of an optimal input mix as the “technical effect.” However, when the uncertainty is of the type that affects all firms in the economy, the technology decision must also explicitly recognize the reaction of the financial markets. In a rate-of-return framework, this market feedback will serve to alter the firm's (or project's) required capitalization rate. This “financial effect” will, for the majority of firms, partially reverse the technical effect. [ABSTRACT FROM AUTHOR]