Interest
Tax Economics:

Taxes are the primary source of revenue for most governments. They are simply defined as a charge or fee on income or commerce. Taxes are most readily understood from the perspective of income taxes or sales tax, although there are many other types of taxes levied on both individuals and firms.

Financial Economics:

Financial economics is a branch of economics that analyzes the use and distribution of resources in markets in which decisions are made under uncertainty. Financial decisions must often take into account future events, whether those be related to individual stocks, portfolios or the market as a whole

Economics:

Economics is the study of how people allocate scarce resources for production, distribution, and consumption, both individually and collectively