As stressed in Chapter 3, under a reasonable general set of conditions, a decentralized market system porvides private goods efficiently. Do market forces lead to the efficient level of public goods(r=45) in Figure 4.4? The answer depends in part on the extent to which Adam and Eve reveal their true preferences for fireworks. When a private good is exchanged in a competitive market, an individual has no incentive to lie about how much he or she values it. If Eve is willing to pay the going price for a fig leaf, then she has nothing to gain by failing to buy one.