Natural resource funds—a subset of sovereign wealth funds—held approximately $4 trillion in assets as of July 2014. This money, which belongs to the public and comes from extraction of non-renewable resources, should serve the public interest. Governments can use these funds to cover budget deficits when resource revenues decline; to save for future generations; to earmark for national development projects; or to help mitigate Dutch disease by investing abroad. They can also be used to reduce spending volatility, in turn improving the quality of public spending, promoting growth and reducing poverty, and protect oil, gas and mineral revenues from corruption. Citizens in Chile, Norway, some Persian Gulf countries and some U.S. states have experienced these benefits.