The cost of holding such large reserves is the interest that could be earned from investing funds in higher-yielding financial assets as well as the potential for otherwise foregone public investment to "crowd in” private investments and reduce inequality. The CTTs and FTTs discussed in the previous section on tax policy can be categorized as capital management techniques.) Tools differacrosscountriesand include reserve requirements on inflows of capital as well as diagnostic tools, such as early warning systems that trigger regulation of capital flows. There is no one-size-fits-all toolkit to manage capital flows, and the approach to the use of such tools has often been dynamic—-that is, countries have flexibly adapted these tools to changes in the internal and external environment.