This paper examines output disparities between the Asia-Pacific Economic Cooperation countries during the period 1990~2011. The results show that inter-country levels of output per capita diverged over the study period but there was a clear break in the trend around 1998. Applying the time-varying individual common factor model, we found that all countries could be grouped into three convergence clubs. Focusing on the time path of each country's output level relative to that of a reference economy such as the United States of America and allowing for possible structural breaks, we found that more countries converged towards the USA during the sub-period 1999~2011. The findings also suggest that the Asia-Pacific Economic Cooperation could have played some role in diminishing the output inequality between its member countries after the Asia-Pacific Economic Cooperation reached its current extent in 1998. Likewise, the paper suggests a need to reduce the wide income gap among the Asia-Pacific Economic Cooperation countries to promote their economic integration.