There is another significant difference between industrialized economies and developing economies which lies in the speed of adjustment. In general, the speed of adjustment in developing countries, particularly on the supply side, is slower than it is in industrialized countries. The reason is simple. Resources are not perfectly mobile across sectors or substitutable in uses, and prices, particularly of factors, are not completely flexible. These problems are accentuated in developing economies which are characterized by structural rigidities. The dynamics of demand are fast in expansion and in contraction. In contrast, the dynamics of supply are slow in expansion (which is partly attributable to the limitations in financial markets) even if somewhat faster in contraction.