Whether one is a conservative or a radical, a protectionist or a free trader, a cosmopolitan or a nationalist, a churchman or a heathen, it is useful… - George Stigler

The state --the machinery and power of the state-- is a potential resource or threat to every industry in the society. With its power to prohibit or compel, to take or give money, the state can and does selectively help or hurt a vast number of industries. That political juggernaut, the petroleum industry, is an immense consumer of political benefits, and simultaneously the underwriters of marine insurance have their more modest repast. The central tasks of the theory of economic regulation are to explain who will receive the benefits or burdens of regulation, what form regulation will take, and the effects of regulation upon the allocation of resources.

The delicate and intricate pattern of competition and cooperation in the economic behavior of the hundreds of thousands of citizens of Stockholm offers a challenge to the economist that is perhaps as complex as the challenges of the physicist and the chemist.

Economic theories are infinitely diverse in their predictive power. Entirely too many have zero predictive power-they are statements of tautologies. Thus the statement that to maximize profits one should operate a firm where marginal revenue equals marginal cost is a mere mathematical statement of the condition for a maximum. The example we gave of search theory is not a tautology because we can identify the factors that influence costs and returns.· Some theories have negative power: they predict the opposite of what happens (and then become useful in the hands of a sophisticated user).