Resuscitating Businessman Risk: A Rationale for Familiarity-Based Portfolios

This paper studies two frequently observed portfolio behaviors that are seemingly inconsistent with rational portfolio choice. The first is the tendency of workers and entrepreneurs to hold their company's stock. The second is the propensity of workers to limit their equity holdings through time. The explanation offered here for both of these behaviors lies in the option to switch jobs when one?s company does poorly. This is equivalent to holding put options on one's own company stock and call options on the other company's stock, where both options must be exercised at the same time. Given these initial undiversified implicit financial holdings, workers need to allocate a relatively large share of their regular financial assets to their own company's stock and a relatively small share to the stock of their alternative employment simply to restore overall portfolio balance. I find that, under certain conditions, workers optimally hold almost 40% of their financial wealth in their company's stock.