RePEc indexes research in Economics, and one usually thinks about publications in journals and pre-prints disseminated by universities through the form of working papers or discussion papers. The fact is that a lot of research is also conducted outside these institutions. Take as an example central banks. Beyond their role of managing the money supply in their respective countries, as well as in some cases operating the payment system and regulating parts of the financial system, they conduct research to facilitate their operations and more generally understand the economy.
Much of this research is also present on RePEc. The following central bank have opened RePEc archives: Australia, Austria, Belgium, Brazil, Canada, Chile, Colombia, Cyprus, Czech Republic, England, France, Greece, Hong Kong, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Lithuania, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Peru, Poland, Spain, Turkey, United States (all Federal Reserve Banks). The following participate through an aggregator: Finland, Germany, Sweden, Switzerland. And finally, the following supranational institutions have a RePEc archive: Bank for International Settlements, European Central Bank, International Monetary Fund. There are plenty of other governmental institutions participating as well, in particular statistical offices, ministries and regulators.