Netikrumas ir neapibrėžtumas ekonominėje politikoje

Abstract

In this paper we want to show and analyze from another point of view one of the limits of the action of a policymaker. We start our analysis considering Lucas’ approach and the Lucas critique (1976) showing the importance of the rational expectations theory. The behavior of private agents is usually forecast not taking into account the consequences of public choices on the parameters of the functions that describe the behavior, thus supposing that the estimated values (through econometric analysis) are not affected by the policy. This implies that these values are given and don’t vary. The Lucas critique points out that a policy can instead change the parameters, underlining that the traditional models does not consider this kind of interaction between the private and the public sector. This active role of the private sector can affect the constraints. Thus the optimal policy ex antedoes not coincide necessarily with the optimal policy ex post: if the variability of the parameters is low, the policymaker can cope with this problem, but the problems arise when the variability is high. Our conjecture is that this problem can be analyzed as an uncertainty (or indeterminacy) related problem, as in physics. To explain it better we focus at first on the role of intermediate targets in economic policies (such as monetary policies) and of rational expectations. We further our analysis providing a model showing the difference between the optimal policy ex ante and ex post when the intermediate task changes, underlining the role of the estimated parameters and the role of uncertainty.