THE RELATIONS AMONG EQUITY MARKETS: A STUDY OF SHARE PRICE CO‐MOVEMENTS IN THE UNITED STATES, UNITED KINGDOM, GERMANY AND JAPAN

Abstract

MOST OF the existing studies on the international capital market are based on a segmented market approach. This approach treats the different national capital markets as separated entities, hardly related to each other. For this reason (under the assumption of market segmentation), comparable capital assets may differ in their return on different national markets. Although market segmentation enjoys a surprisingly large following, it is not the only possible interpretation of the international capital market. The alternative hypothesis, i.e., that prices of capital assets in the international capital market behave as if there is one multinational perfect capital market, should be considered. The one market hypothesis has the advantage of being consistent with much of the accepted economic theory. Also the one market hypothesis is unambiguous where market segmentation can stand for any number of specific imperfect market formations. Market segmentation is widely accepted as the only possible structure of the international capital market. Different currency areas, separated political organizations and trade barriers have been given as a priori evidence for the segmentation of the international capital market. This, however, is not necessarily the case. An examination of the behavior of capital asset prices reveals that the price behavior is consistent with the one market hypothesis. It should be noted, however, that a certain body of data can be consistent with both the one market hypothesis and any one of several specific forms of market segmentation. But as the main theme of this study is to show the validity of the one market approach to the multinational equity market, it is sufficient to show that one cannot reject the one market hypothesis with regard to this market.