As with patents, we are interested here in the aspects of tariffs that Tucker neglected: their effect in promoting the cartelization of industry. In the next chapter, on the rise of monopoly capitalism, we will see the full-blown effects of what Schumpeter called "export-dependent monopoly capitalism." That term refers to an economic system in which industry cartelizes behind the protection of tarriff barriers; sells its output domestically for a monopoly price significantly higher than market-clearing level, in order to obtain super-profits at the consumer's expense; and disposes of its unsellable product abroad, by dumping it below cost if necessary.

The tariff was commonly called "the mother of trusts" by the populists of a century ago, because of the way it facilitated collusion between large domestic producers and the creation of oligopolies. Mises, in Human Action, described the dependence of cartels on tariff barriers (especially interacting with other state-enforced monopolies like patents). Of course, in keeping with his usual "pro-business" emphasis, Mises treated the large industrial firms, at worst, as passive beneficiaries of a state protectionist policy aimed primarily at raising the wages of labor. This parallels his view of the early industrial capitalists, and their non-implication in the primitive accumulation process, in the previous chapter.

According to Kolko's account in The Triumph of Conservatism, the large trusts at the turn of the twentieth century were not able to maintain their market share against more efficient smaller firms. The stabilization of most industries on an oligopoly pattern was possible, in the end, only with the additional help of the "Progressive" Era's anti-competitive regulations. The fact that the trusts were so unstable, despite the cartelizing effects of tariffs and patents, speaks volumes about the level of state intervention necessary to maintain monopoly capitalism. But without the combined influence of tariffs, patents, and railroad subsidies, it is unlikely they would have been able to make even a credible attempt to organize such trusts in the first place.