In a 2005 effort to reinvigorate new-member organizing efforts, seven unions split from the American federation of labor and congress of Industrial Organizations (Afl-cIO) to form a new union federation, change to Win. Using ten years of data from the national labor Relations Board and the national Mediation Board and a difference-in-difference estimator, the author estimates the effect of change to Win policies on whether a union won its certification election and the number and percentage of workers successfully organized. The results indicate no statistically significant difference in organizing success following change to Win's implementation of new organizing strategies and practices, relative to the Afl-cIO. l abor unions in the United states have a complex history of prioritizing new-member organizing. After a sharp increase in organizing activity following the enactment of the national labor Relations Act in 1935, unions' prioritization of organizing began to wane. More notably, unions' financial investment in new-member organizing began to decrease in the 1950s; organizing expenditures per nonunion worker decreased approximately 28% between 195328% between and 197128% between (Atleson 1994. Accompanying this decreased prioritization of new-member organizing was a decline in union density (farber and Western 2001).for decades, academics and unionists have chronicled the decline in union density in the United states; union leaders have begun to see newmember organizing as a potential solution and everyday priority, and academics have begun to study these organizing attempts. such research has included quantitative assessments of the effect of specific organizing tactics or strategies on union election wins (Reed 1989;