On the causes of the changes in income shares: Some reflections in the light the United States experience

The last 30 years have witnessed a dramatic change in the distribution of income, with the wage share falling in all major industrialized countries. Main-stream analyses, including New Keynesian ones, which retain the notion of factor substitution leading to a “factor intensity” inversely related to its rate of return, have encountered some difficulties in the interpretation of this change. Nonmainstream approaches present an advantage in the explanation of the phenomenon, consisting in the fact that they entail no a priori connections between the changes in distribution and the changes factor proportions. Hence if a change in institutions or in the bargaining strength of the parties affects distribution, income shares may vary significantly (i.e., changes in wages need not be accompanied by changes in labor to output ratio in the opposite direction as in mainstream analyses). Yet empirical observation may question also some of the analyses that have been advanced outside the mainstream. The article will explore the ways in which nonmainstream approaches have interpreted the described changes in distribution, and assess them from an analytical viewpoint and with reference to U.S. data. The purpose is that of pointing at some open questions and problems.