IDPR, 32 (3–4) 2010 doi:10.3828/idpr.2010.06 Victoria A. Beard and Carolina S. Sarmiento Ties that bind: transnational community- based planning in Southern California and Oaxaca Victoria A. Beard is Associate Professor and Carolina S. Sarmiento is a Ph.D. student in the Department of Planning, Policy and Design, School of Social Ecology at the University of California at Irvine, Irvine, California 92697-7075, USA; email: vbeard@uci.edu; csarmien@uci.edu Much of the community-based planning literature focuses on the development of collaborative social relationships in small territorial communities. It is argued that the collective action that is foundational to such planning is based on closed social relationships, trust and the ability of participants to control or punish potential defectors. The article examines how community-based planning and the social relation- ships that underlie it emerge and are maintained transnationally. The research focuses on immigrants from Oaxaca, Mexico, who have relocated to Southern California and established hometown associa- tions. The associations remit money to their pueblos of origin for community-based planning. The article examines (1) how social networks and the relationships of trust upon which they are built connect immigrants in California to their pueblo of origin, (2) how these social relationships that facilitate commu- nity-level collective action are maintained across transnational spaces and (3) the potential of such collec- tive action for broader social and political transformation in Southern California and Oaxaca. Over the last half century, development planning scholarship and practice have shifted away from centralised, state-controlled, top-down planning toward decentralised, community-based and grassroots planning (Scott, 1998; Tendler, 1997). The shift rests on a complex set of assumptions about the relationships among spatial scale, efcacy and equity (Beard et al., 2008). First, it is assumed that local entities are in a better position than are centralised state agencies to make planning and resource allocation decisions, because their geographic proximity facilitates a better understanding of community dynamics and needs (Kingsley, 1996; Manor, 1999). Second, communities are assumed to be small, geographically contained units (Ostrom, 1990). Third, it is assumed that the shared territorial base of a community helps facilitate closed and stable, social relationships (Agrawal, 2001; Coleman, 1990). A growing number of scholars and practitioners have started to question the transformative power of community-based planning and development (Beard, 2007; Cooke and Kothari 2002; Davis, 2006; Miraftab, 2004; Sanyal, 2007). Cleaver (1999, 597) summarises the critique: ‘Despite signifcant claims to the contrary there is little evidence of the long-term efectiveness of participation in materially improving the conditions of the most vulnerable people or as a strategy for social change.’ These scholars question the usefulness of the ideological shift from state planning to more local, micro and community-based approaches. They point out that even though the IDPR32_3-4_01_Beard.indd 207 15/10/2010 10:16