Trade integration and research and development investment as a proxy for idiosyncratic risk in the cross-section of stock returns

Although consumption-based asset pricing constitutes a solid body of work for the purpose of relating asset prices and macroeconomics, most empirical tests put into question the representative investor perspective. Furthermore, most approaches accounting for untraded risks, such as the Constantinides-Duffie model, face the problem of correctly quantifying idiosyncratic risk. In this paper we exploit the strong relationship of income inequality with trade openness and research and development (R&D) investment to proxy the cross-sectional variance of consumption growth by the growth rate of imports plus exports (trade openness) and the growth of the domestic expenditure in R&D. Moreover, we use these variables as a part of the information set used by investors to determine the unconditional version of the conditional consumption-capital asset pricing model (CCAPM). Our results show that both trade openness and R&D investment allow the linearized version of the Constantinides-Duffie model and the conditional CCAPM to greatly outperform the classic CCAPM for different sorts of stock portfolios, contributing significantly to reducing pricing errors. Hence, our results constitute a step forward in the attempt to relate asset prices and income inequality in a tractable way.