In 1970 the New York Stock Exchange relaxed rules that prohibited the public incorporation of member firms. Investment banking concerns went public in waves, with Goldman Sachs the last of the bulge bracket banks to float. We explain the pattern of investment bank flotations. We argue that partnerships foster the formation of human capital and we use technological advances that undermine the role of human capital to explain the partnership's going‐public decision. We support our theory using a new data set of investment bank partnership statistics.

We study how the creation of an internal capital market (ICM) can invite strategic responses in product markets that, in turn, shape firm boundaries. ICMs provide ex post resource flexibility, but come with ex ante commitment costs. Alternatively, stand‐alones possess commitment ability but lack flexibility. By creating flexibility, integration can sometimes deter a rival's entry, but commitment problems can also invite predatory capital raising. These forces drive different organizational equilibria depending on the integrator's relation to the product market. Hybrid organizational forms like strategic alliances can sometimes dominate integration by offering some of its benefits with fewer strategic costs.