A cynic might say of free competition what Bernard Shaw once said of Christianity: the only trouble with it is that it has never been tried. There never was a golden age of free competition, and competition is not now perfect in the economist's sense; probably it is becoming less so every day, in large part because of the fundamental nature of large-scale production and technology, consumers' tastes, and business organization.

This does not mean that we must accept as inevitable the trend toward big business, mergers, trusts, and cartels that began to swell in the 1890's. We may not believe ourselves captains of our souls, but at least we can try to be first mates. Vigorous and intelligent administration of antitrust legislation may stem the ride; but it is like the dog baying at the moon to expect universal creation of the atomistic conditions that we shall see are necessary for perfect or pure competition. It will not be easy, but our imperfectly competitive system can be helped to work better. By itself, this will not solve the problem of unemployment or purchasing power, as is developed at length in the saving-investment analysis in Part Two.

— Paul Samuelson (1915 – 2009)
Economics: The Original 1948 Edition