DIFFERENCE BETWEEN INTERNAL AND EXTERNAL TRADE (1)Mobility of factors of production ;Generally speaking ,as compared to the international level of mobility ,factors internally are more freely mobile .in this case of labor, mobility is rather difficult due to the existence of immigration laws .for example the availability of work permits at international level is rather difficult .in the case of capital ,although it is more easily mobile ,but usually one would prefer to the invest in his own country ,inter alia .he feels rather to do so likewise and moreover the Government generally encourages people to invest internally rather than externally .land ,of course ,is virtually immobile at international level and even at an internal level .However ,generally speaking ,other obstacles which exist are e.g. culture ,language and other formalities .Moreover ,free mobility with in the country leads to equality in the costs of production . (2)Problem of conversion of currency: In the case