Boundaryless careers, social capital, and knowledge management: Implications for organizational performance MILA LAZAROVA 1 * AND SULLY TAYLOR 2 1 Faculty of Business Administration, Simon Fraser University, Burnaby, BC, Canada 2 School of Business Administration, Portland State University, Portland, OR, U.S.A. Summary The purpose of this paper is to critically assess the utilization of boundaryless careers in organizations through the lens of how they impact the formation and deployment of organizational social capital. We build a model of the positive and negative effects of boundaryless careers on social capital formation by proposing a more nuanced picture of boundaryless careers. We divide boundaryless careers into four types: internal psycho- logical, internal enacted, external psychological and external enacted. Our model delineates the conditions under which different types of boundaryless careers affect the formation and deployment of organizational structural, relational and cognitive social capital and offer propositions based on our analysis. In addition we examine type of knowledge (exploratory or exploitative) pursued by the firm as a key moderator for the relationships we propose. Copyright # 2008 John Wiley & Sons, Ltd. Introduction With few exceptions, research on boundaryless careers has been at the individual level. It has emphasized their positive impact, implying that they create many developmental opportunities for individuals – and, by extension, have many benefits for organizations and industrial sectors (Cohen & Mallon, 1999). Their potential negative aspects have received considerably less attention. The purpose of this paper is to critically assess the use of boundaryless careers in organizations through the lens of how they impact organizational social capital, a critical prerequisite for organizational success in a global economy (Kogut & Zander, 1992, 1996; Kostova & Roth, 2003; Nahapiet & Ghoshal, 1998). We propose a theoretical model that specifies the conditions under which boundaryless careers enhance or damage social capital in organizations. We argue that important differences exist between attitudes regarding boundary-crossing and actual boundary-crossing behaviors and between internal and external organizational boundary-crossing. We put forward a typology of boundaryless careers and argue that the type of boundaryless career has consequences for the formation and utilization of organizational social capital. Organizational social capital plays a significant role in Journal of Organizational Behavior J. Organiz. Behav. 30, 119–139 (2009) Published online 23 July 2008 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/job.545 *Correspondence to: Mila Lazarova, Faculty of Business Administration, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6. E-mail: mbl@sfu.ca Copyright # 2008 John Wiley & Sons, Ltd. Received 2 March 2007 Revised 15 April 2008 Accepted 20 May 2008