One possibility--though I'm sure there are others that my fellow Radical Reference volunteers will think of--is the work done by Michael Albert on participatory economics. His most recent book on the subject is Parecon: Life After Capitalism, which was published in 2003. He has also written and/or produced several other books and videos on the subject, and there is a whole page devoted to parecon on ZNet.

A subject search for Economic policy--Citizen participation in any library catalog (the results I've linked to are from WorldCat, which includes the holdings of many, though not all, of the libraries in the US) looks like it might also yield some interesting and helpful results.