Why worry that we are moving toward a society in which everything is up for sale?

For two reasons. One is about inequality, the other about corruption. First, consider inequality. In a society where everything is for sale, life is harder for those of modest means. The more money can buy, the more affluence—or the lack of it—matters. If the only advantage of affluence were the ability to afford yachts, sports cars, and fancy vacations, inequalities of income and wealth would matter less than they do today. But as money comes to buy more and more, the distribution of income and wealth looms larger.

The second reason we should hesitate to put everything up for sale is more difficult to describe. It is not about inequality and fairness but about the corrosive tendency of markets. Putting a price on the good things in life can corrupt them. That’s because markets don’t only allocate goods; they express and promote certain attitudes toward the goods being exchanged. Paying kids to read books might get them to read more, but might also teach them to regard reading as a chore rather than a source of intrinsic satisfaction. Hiring foreign mercenaries to fight our wars might spare the lives of our citizens, but might also corrupt the meaning of citizenship.

Economists often assume that markets are inert, that they do not affect the goods being exchanged. But this is untrue. Markets leave their mark. Sometimes, market values crowd out nonmarket values worth caring about.

When we decide that certain goods may be bought and sold, we decide, at least implicitly, that it is appropriate to treat them as commodities, as instruments of profit and use. But not all goods are properly valued in this way. The most obvious example is human beings. Slavery was appalling because it treated human beings as a commodity, to be bought and sold at auction. Such treatment fails to value human beings as persons, worthy of dignity and respect; it sees them as instruments of gain and objects of use.

Something similar can be said of other cherished goods and practices. We don’t allow children to be bought and sold, no matter how difficult the process of adoption can be or how willing impatient prospective parents might be. Even if the prospective buyers would treat the child responsibly, we worry that a market in children would express and promote the wrong way of valuing them. Children are properly regarded not as consumer goods but as beings worthy of love and care. Or consider the rights and obligations of citizenship. If you are called to jury duty, you can’t hire a substitute to take your place. Nor do we allow citizens to sell their votes, even though others might be eager to buy them. Why not? Because we believe that civic duties are not private property but public responsibilities. To outsource them is to demean them, to value them in the wrong way.