The 2013 ISA Convention held in San Francisco reflects the diversity of diffusion research, spanning wide-ranging thematic and methodological interests related to diffusion at the global and regional levels. Klinger-Vidra and Schleifer differentiate between models of diffusion that assume the existence of a single initial source and those that involve multiple sources. Goldsmith distinguishes between first- and second-order diffusion. The first-order diffusion of trade liberalization and export-led growth development strategies in the 1970s, he argues, had a second order effect on international relations in East Asia, making the escalation of interstate conflicts less likely. Forsberg and Mekouar focus on stimuli. Forsberg argues that the eruption of internal conflict in one location is better explained by previous internal conflict in another location than by the spatial clustering of factors related to conflict, such as poverty.