The purpose of this paper is twofold: first, to develop a new HappinessIndicator that assesses the happiness level and condition of the Korean people bysystematizing the positive and negative factors; second, to identify which factorsare determinant in increasing or decreasing the happiness level of Koreanscompared to the OECD member countries. We found that positive factors ofhappiness have a significant positive effect on happiness levels for the OECDcountries, while negative factors of happiness have a positive effect for Koreaand similar countries. As a result, it was confirmed that the happiness indicatorincluding the negative factors proposed in this paper is valid for understandingthe happiness level of Koreans.