IN a recent article appearing in this Journal, Holl [2] tests the proposition that firms which are controlled by professional managers will fail to maximise profits. Several studies in the US have concluded that the separation of ownership from control has had little or no effect on company profitability, and Holl's main point is that these have failed to consider the restraint im- posed by the market for corporate control. Holl argues that when this is done the hypothesized non-profit maximising behaviour of professional managers is demonstrated, although the extent of the effect is less general than lhas been thought (i.e. it is limited to those management controlled companies which can evade the discipline of the market). The purpose of this note is to show that proponents of the separation thesis should not be heartened by the result achieved by Holl, since it is heavily dependent on the form which his hypo- thesis takes.