Corporate mergers, stockholder diversification, and changes in systematic risk

Abstract Strategic management literature suggests a relationship between systematic risk and the relatedness of merging firms. This is tested for a sample of 120 large mergers by controlling for the systematic risk of the target firm, correcting for possible problems of heteroskedasticity, and estimating shifts in risk over daily as well as monthly time horizons. Finally, the influence of leverage is considered. The findings highlight a performance distinction between corporate diversification and stockholder diversification in instances of related and unrelated mergers.