Economies of scale refers to the cost advantages that an enterprise obtains due to expansion. There are factors that cause a producer's average cost per unit to fall as the scale of output is increased. Economies of scale is a long run concept and refers to reductions in unit cost as the size of a facility and the usage levels of other inputs increase. Economies of scale is also a justification for economic integration, since some economies of scale may require a larger market than is possible within a particular country — for example, it would not be efficient for Liechtenstein to have its own car maker, if they would only sell to their local market. A lone car maker may be profitable, however, if they export cars to global markets in addition to selling to the local market.