Forever Stamps are always sold at the same price as a regular First-Class Mail stamp. The Postal Service developed the Forever Stamp for consumers ease of use during price changes. Forever Stamps are available for purchase at post offices nationwide, online at usps.com, and by phone at 1-800-STAMP-24 (1-800-782-6724).
Production Possibility curves. The production possibility curves is a hypothetical representation of the amount of two different goods that can be obtained by shifting resources from the production of one, to the production of the other. The curve is used to describe a societys choice between two different goods. Figure 1, shows the two goods as consumption and investment.
Since the production possibilities frontier represents all of the points where all resources are being used efficiently, it must be the case that this economy has to produce fewer guns if it wants to produce more butter, and vice versa. The slope of the production possibilities frontier represents the magnitude of this tradeoff. For example, in moving from the top left point to the next point down the curve, the economy has to give up production of 10 guns if it wants to produce 100 more pounds of butter. 1  Not coincidentally, the average slope of the PPF over this region is (190-200)/(100-0) = -10/100, or -1/10.