This paper provides a framework and some empirical evidence to evaluate the seriousness of problems in inference that arise in stockreturn-based studies when the data are cross-sectionally dependent. The study is motivated on the grounds that statistical procedures designed to address such problems are often infeasible, and even when they can be implemented they sometimes introduce other more serious difficulties. Thus, researchers have frequently adopted an approach that ignores the cross-sectional dependence (e.g., ordinary least squares [OLS]). The objective of this paper is to help identify the contexts in which ignoring the dependence would lead to serious misstatement of significance levels. Cross-sectional dependence in stock returns data is likely to exist when at least some of the returns are sampled from common time periods. This would be the case in all studies of the reaction of stock prices to a

Victor L. Bernard, Thomas J. Frecka, Commodity Contracts and Common Stocks as Hedges against Relative Consumer Price Risk, The Journal of Financial and Quantitative Analysis, Vol. 22, No. 2 (Jun., 1987), pp. 169-188

Previous investigations of the incremental information content of current cost Income have focused on cross-sectional analyses, which assume that the relation between stock returns and specific price-level adjustments is the same for all firms. Beaver et al. [1982] suggest that such analyses may be misspecified and provide preliminary indications that the Incremental information content of current cost Income may be more evident in a time-series context. The study summarized here provides the first formal examination of the information content of current cost income and historical cost Income within a time-series context. Some evidence of Incremental information content in current cost income is found in the time-series analysis, even though none is evident in a cross-sectional analysis. However, incremental Information content is (at best) evident only for a small subset of industries where the correlation between historical cost income and current cost income is low; for the majority of industries, the two income measures convey essentially the same information.

[Previous investigations of the incremental information content of current cost income have focused on cross-sectional analyses, which assume that the relation between stock returns and specific price-level adjustments is the same for all firms. Beaver et al. [1982] suggest that such analyses may be misspecified and provide preliminary indications that the incremental information content of current cost income may be more evident in a time-series context. The study summarized here provides the first formal examination of the information content of current cost income and historical cost income within a time-series context. Some evidence of incremental information content in current cost income is found in the time-series analysis, even though none is evident in a cross-sectional analysis. However, incremental information content is (at best) evident only for a small subset of industries where the correlation between historical cost income and current cost income is low; for the majority of industries, the two income measures convey essentially the same information.]