Some economists are trying to explain this behavior. Usually, the explanation is based on a sophisticated variation of mercantilism, such as to protect the take-off in the tradable sector of an economy, by avoiding the real exchange rate appreciation that would naturally arise from this process. One attempt uses a standard model of open economy intertemporal consumption to show that it is possible to replicate a tariff on imports or a subsidy on exports by closing the capital account and accumulating reserves. Another is more related to the economic growth literature. The argument is that the tradable sector of an economy is more capital intense than the non-tradable sector. The private sector invests too little in capital, since it fails to understand the social gains of a higher capital ratio given by externalities (like improvements in human capital, higher competition, technological spillovers and increasing returns to scale). The government could improve the equilibrium by imposing subsidies and tariffs, but the hypothesis is that the government is unable to distinguish between good investment opportunities and rent seeking schemes. Thus, reserves accumulation would correspond to a loan to foreigners to purchase a quantity of tradable goods from the economy. In this case, the real exchange rate would depreciate and the growth rate would increase. In some cases, this could improve welfare, since the higher growth rate would compensate the loss of the tradable goods that could be consumed or invested. In this context, foreigners have the role to choose only the useful tradable goods sectors.