Now that we have seen the way a competitive economy allocates resources,
Gucci Hobo handbags, we can understand why a competitive economy is efficient.
A general-equilibrium market system will display allocative efficiency when there is perfect competition, with well-informed producers and consumers and no external effects. In such a system, each good's price is equal to its marginal costs and each factor's price is equal to the value of its marginal product. When each producer maximizes profits and each consumer maximizes utility, the economy as a whole is efficient. No one can be made better off without making someone else worse off.
What is the reason for this surprising coincidence between public welfare and private interest? We can easily see the logic by using an example. Suppose some economic wizard comes forth and says, "I have found a way of reorganizing the perfectly competitive economy to make everyone better off. We are producing too few pizzas. Simply give everyone more pizzas and fewer shirts and everyone will be better off."
But the self-proclaimed wizard is mistaken. Suppose the current price of shirts is $15,
Belstaff Icon Jackets, while the price of pizzas is $5. On the consumer's side, each individual has allocated his or her budget so that the marginal utility of the last pizza is just one-third of the marginal utility of the last shirt. So consumers would certainly not want to have more pizzas and fewer shirts unless they could get more than three pizzas for each shirt given up.
Can the economy squeeze out more than three pizzas for each forgone shirt? Not if it is competitively organized. Under perfect competition, the ratio of the price of shirts to the price of pizzas is the ratio of the marginal costs of the two goods. Hence,
MBT Kisumu Sandals, if their price ratio is $15/$5 = 3, producers can squeeze out only three more pizzas for each shirt not produced. Indeed, if the production-possibility frontier is bowed out, producers will actually get somewhat less than three pizzas for every shirt forgone.
So we see why our wizard is wrong. Consumers are willing to eat more pizzas and have fewer shirts only if they can improve their satisfactions, which mean that they must get more than three pizzas for every shirt forgone. But this is not possible because profit-maximizing producers cannot get more than three pizzas by producing one less shirt. Therefore the proposed reorganization will not improve everybody's economic satisfaction.
The reasoning, of course, extends far beyond pizzas and shirts. With a little thought, you can see that it works as well for all consumer goods. With a little more work, you can even see how it will extend to include reorganizations of inputs and production across firms. And it is easy to see that it would apply to trade among nations as well as trade within a nation.
The basic point to see is that, because prices serve as signals of economic scarcity for producers and social utility for consumers, a competitive price mechanism allows the best mix of goods and services to be produced from a society's resources and technology.