Main Street is not merely a thoroughfare. Here one can enjoy the pleasures of social life, here one can produce things of value, here one can put one's savings to productive use. It is more than a location, it is an opportunity to render and to receive services. The opportunity is sought after, and the intensity of desire for sites on Main Street fixes rental value. The bids do not represent a charge on the occupier's income, wages on his labor, or interest on his investment, but rather measure the opportunity which the desired spot will give him to work and to invest his capital. It is for the opportunity that he is willing to pay a share of the production made possible by the location. The opportunity costs him nothing, because if he did not apply his skills and his capital there, if he were compelled to locate "off the beaten track," his returns would be commensurately less. If he has rare skill to offer, like singing, it is necessary that he display it here, for elsewhere customers would be few. If he has much capital to invest, he puts up his building or his haberdashery shop at this center of population because on the prairie his capital would be unproductive. He pays for the opportunity to produce out of the production the site makes possible, not out of his earnings. In point of fact, the rent comes in by the front door.
Main Street—used here as a symbol of the market economy—is made possible by population. Population concentrates in the locality, in the first place, because the locality promises a return on invested labor and capital, because it has good land, a harbor, a mine or, eventually, a factory. That is the first magnet for people. But, since men do not live by bread alone, the wages earned in the locality begin clamoring for services that only Main Street can provide, and as wages increase so does the clamoring. Among the services 106