Although the human capital approach became popular in the 1970s, eventually the institutional and structural approach dominated the analysis of wages in Japan. Statistical measurement (econometric) problems are numerous in human capital theory: censoring bias, omitted variables, endogeneity, job match heterogeneity, and the like. Internal labor markets, dualism, and segmentation explains various facets of Japanese wage determination in varying degrees of success. Some wage analysts used an "ad hoc", combination of human capital theory in combination with the institutional framework to explain the specific characteristics of the Japanese wage system. The main weakness of the institutionalist approach is the limited ability of the descriptive (empirical) methods to explain the evolution and direction of wages with respect to social and industrial relations. During periods of rapid economic growth in Japan, wage increases had been well explained by the demand-supply conditions in labor markets. The job offer-application ratio acted as a proxy for excess labor demand, and indirectly for the level of aggregate production. This equation however lost its explanatory ability after the first oil crisis. Since then, consumer prices, enterprise profits and terms of trade (input and output prices) had high explanatory power until the second oil crisis. In the 1980s, analysts observed a certain degree of wage flexibility in Japan. The ability of conventional quantitative approaches to identify the factors which explain this flexibility has decreased, pointing to the possibility of qualitative variables such as "consensus" and "accomodation" having a greater role in Japanese wage determination. This would obviate the role of an apparent decline in trade union strength as a factor behind such flexibility. Structural and qualitative changes in the Japanese labor force, and the increasing use of managerial strategies and techniques are seen to be the relevant factors in contemporary wage determination in Japan.