QUALITATIVE COMPARATIVE STATICS

Given the system Ax = b, assume that qualitative (+, -, 0) information is available concerning the entries in A and b. The comparative stati cs problem is to solve for the sign pattern of x (full sign solvabilit y) or of a subset of x (partial sign solvability). The paper derives n ecessary and sufficient conditions for full and partial sign solvabili ty in the purely qualitative case; and where A is negative definite or negative definite under constraint. Also the paper identifies the cla ss of qualitative matrices for which stability implies Hicksian stabil ity, and examines the comparative statics properties of such systems.