The purposes of this research were to study 1) factors affecting happiness 2) role of membership as a moderator of the relationship between different factors and happiness 3) association between socio-demographic factors and happiness. Data were collected via Senasu’s survey (2017). The samples of this research were 200 residents of a community in Bangkok and 200 Thai rotary members club in Bangkok. The collected data were analyzed with descriptive and inferential statistics, including hierarchical regression and analysis of variance. The results ...