An unpleasant small-stock effect in manufacturing: the case of the dependent buyer

Purpose The purpose of this paper is to determine if there is a significant difference in the investment risks between small-cap manufacturers that heavily depend on one or a few buyers, referred to as “dependent-buyers,” and small-cap manufacturers that have a more diversified customer base. If there is a significant difference both statistically and economically, then investors need to be aware of the dependent-buyer effect in their security selection and portfolio construction efforts. Design/methodology/approach Using large samples of firm-level data from 2000 through 2011, the authors employ standard risk estimation modeling to compute β s, idiosyncratic risks, and total risks of both dependent-buyer firms and firms with a more diversified customer base. Findings The authors find that the β s, idiosyncratic risks, and total risks of dependent-buyer firms are much greater than that of firms not in dependent relationships. These differences are both statistically and economically significant. Research limitations/implications Buyer-supplier relationships can change quickly, and so a firm that has a diversified base in one period, for example, could be a dependent-buyer in the next period. Much depends on the reporting accuracy of firms and the ability of the securities exchange commission (SEC) to track the relationships. Practical implications First, the risk of individual small-cap stocks is likely to be greater than perceived from macro-level data, leading to the need for more securities if idiosyncratic risk is to be eliminated. Second, small-cap investors have the opportunity to enhance portfolio construction efficiency by referencing data published by the SEC. Third, most investors interested in small-cap manufacturing stocks should find it prudent to allocate a large percentage of their small-cap investments to an index fund. While this may sacrifice higher returns, it also reduces the probability of experiencing an unpleasant small-stock effect. Originality/value This is the first study to show that the difference in investment risks between small-cap manufacturers that depend on one or a few firms for their outputs and small-cap manufacturers that have a well-diversified customer base is statistically and economically significant, information that should be valuable to investors in their security selection and portfolio construction efforts.