A think tank (also calle a policy institute) is an organization, institute, corporation, or group that conducts research and engages in advocacy in areas such as social policy, political strategy, economy, science or technology issues, industrial or business policies, or military advice. Many think tanks are non-profit organizations, which some countries such as the US and Canada provide with tax exempt status. While many think tanks are funded by governments, interest groups, or businesses, some think tanks also derive income from consulting or research work related to their mandate.