[In this paper we consider the problem of the existence of a well-defined reduced form in the context of piecewise linear models. We give a general theorem which provides necessary and sufficient conditions, called coherency conditions, for such an existence. This result is applied to various kinds of models: self-selectivity models, simultaneous equation probit and tobit models, multimarkets disequilibrium models.]

This paper considers the econometric problems raised by multi-market disequilibrium models. It uses a specification which is derived from general disequilibrium theory and, therefore, provides a first bridge between the economic theory approach and the econometric theory approach of disequilibrium. The model is piecewise linear; the problem of the existence of a reduced form, which is a crucial issue in nonlinear models, is solved. Limited information estimators as well as full information estimators are proposed; a simple numerical algorithm is given for the computation of a FIML estimator.