In order to appreciate the effects of displacement fully, it is necessary to extend our imaginations beyond the limits implied by existing non-free-market economies. Suppose, for instance, that "free" groceries were provided by taxpayer-subsidized government stores. Clearly, the vast majority of citizens would find it most economical to purchase their groceries in such stores. Private grocery stores as we know them today would be virtually non-existent, although a few gourmet shops, catering to the affluent, might provide specialized products not available in the public stores. Under such circumstances, it is likely that most people would find the very notion that grocery items could be mass-marketed privately to be ludicrous. In today's society, a similar failure of imagination makes it difficult for many people to comprehend that education or postal service could be supplied on a large scale by the free market.