Derek Jones is an New York-based economist who studies worker cooperatives, often from the perspective of participation and productive efficiency.  He is an active member of the International Association for the Economics of Participation, an organization that holds conferences (2010, 2008, 2006) and publishes the annual journal Economic Analysis: Journal of Enterprise and Participation.  Here are a few of Jones' works from his website.  

• Co-operatives and Employee Ownership "forthcoming, International Encyclopedia of Civil Society," edited by Helmut K. Anheier and Stefan Toepler, Springer. - Derek Jones and Panu Kalmi
• The Productive Efficiency of Italian Producer Cooperatives: Evidence from Conventional and Cooperative Firms Advances in the Economic Analysis of Participatory and Labour Managed Firms, vol.10, 2007, pp.3-28 - Derek Jones
• How Does Employee Involvement Stack Up? The Effects of Human Resource Management Policies on Performance in a Retail Firm (with Panu Kalmi and Antti Kauhanen) Industrial Relations vol. 49:1, 2010, pp.1-21 - Derek Jones
• The Effects of Employee Involvement on Firm Performance: Evidence from an Econometric Case Study (with Takao Kato) "forthcoming, Industrial and Labor Relations Review." - Derek Jones