Perhaps his most famous book was The New Industrial State, in which he argues that some of the larger firms in the United States form what he called the “technostructure.” The technostructure firms were widely held, by many stock owners, few of whom had the incentive or power, to closely monitor whether the firms’ managers were serving the stock owners by maximizing profits. As a result, the technostructure firms’ managers were free to pursue other goals, such as their own power. (Galbraith was OK with the assumption that firms outside the technostructure were maximizing profits.)
Harold Demsetz tested this hypothesis by comparing the rate of profit of firms in and out of the technostructure, reasoning that if technostructure firms were not maximizing profits, we would expect their profits to be lower than those of other firms. He found that there was no difference between the rate of profits of the so-called ‘technostructure’ firms, and the non-technostructure firms. Demsetz’s conclusion was that there was no distinguishable technostructure, and no new industrial state.