strongly discouraged. However, there is no global framework to regulate financial flows. As an example of regional framework, members of the European Union are prohibited from introducing capital controls, except in an extraordinary situation. The dynamics of China's trade balance and reserve accumulation during the first decade of the 2000 was one of the main reasons for the interest in this topic. 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. Intergenerational savings Reserve accumulation can be seen as a way of "forced savings". The government, by closing the financial account, would force the private sector to buy domestic debt for lack of better alternatives. With these resources, the government buys foreign assets. Thus, the government coordinates the savings accumulation in the form of reserves. Sovereign wealth funds are examples of governments that try to save the windfall of booming exports as long-term assets to be used when the source of the windfall is extinguished. Costs There