Canadian pension fund assets are estimated at just under $500 billion and are second only to the combined financial assets of the major banks in Canada. These pension funds have become a critical source of capital for national and international markets. They are controlled by an intricate web of financial and legal standards such as fiduciary responsibility and yet as deferred wages, are largely beyond the control of workers or their unions.This study argues that, given their tax-exempt status, pension funds can provide the long-term capital needed to build a new economy based on real productivity. To test this assumption, a participatory research methodology was applied to a real estate development company in British Columbia funded through the pooling of capital from 26 pension funds with union trustees. The study focused on investments targeted to a working class community in Vancouver. Social accounting models were used, broadening the criteria normally used in traditional accounting practice.It was found that the company doubled its direct, attributable hours of employment in indirect and induced hours of work in the community. Further, its contribution to community productivity was more than double its total cost over a ten year period. This net social gain was calculated based on the differing social and economic value to the community of construction of rental accommodation and market housing. Finally, for all levels of government, tax revenues from Concert and Mortgage fund One far outweigh foregone taxes through pension fund contributions and investment returns.A social action model for union control of pension fund investment illustrates the major components that enable union trustees to invest pension funds for social, or collateral benefit. These components are leadership, social support and expertise, and education. The study recommends strong educational programs for pension trustees in social investment strategies.