Among economic phenomena which have in some way been tied up with the existence of uncertainty, three classes may be distinguished: (1) those which b… - Kenneth Arrow

The implications for planning are ambiguous. On the one hand, the optimal allocation under increasing returns will not be obtained under free markets. In fact, as I have already remarked, the competitive equilibrium is not even viable, and the outcome will be some kind of imperfect competition. But optimal allocation under increasing returns is difficult. For one thing, the optimisation requires the use of integer programming, a procedure intrinsically more complex than linear programming, and impossible to carry out for large systems even with the most powerful computers. Even more serious are the data demands. The information needed is widely dispersed among the industries and cannot be effectively communicated. It is for these reasons that decentralised decision-making with some element of monopoly is likely to be more efficient.

Dynamic analysis may have deeper implications if we depart from the analysis of stationary states. The frim must now serve some additional roles. In the absence of futures markets, the firm must serve as a forecaster and as a bearer of uncertainty. Further, from a general equilibrium point of view, the forecasts of others become relevant to the evaluation of the firm's shares and therefore possibly of the firm's behavior.

Government economic policy, like almost any realistic decision problem, has two fundamental characteristics: it is sequential and it is uncertain.