Mercantilism is a social policy in Civilization V. It is part of the Commerce tree and requires Mercenary Army. The introduction of mercantile practices in a nation adds a protective layer of taxes and bureaucratic procedures for goods imports and foreign traders which aims at promoting national trade, instead of depending on foreign merchants. The result is a very satisfied national merchant class, and they return the favor by providing additional financing for local governments when they wish to finish quickly some projects. Another beneficial effect is observed in the nation's financial institutions, such as banks and stock exchanges, in which young economists dig into the scientific basis of trading and produce some amazing research results. If not additional wealth...