Increasing evidence from the empirical economic and psychological literature suggests that positive and negative well-being are more than opposite ends of the same phenomenon. Two separate measures of the dependent variable may be needed when analyzing the determinants of subjective well-being. We argue that this conclusion reflects in part the use of too restrictive econometric models. A flexible multiple-index ordered probit panel data model with varying thresholds can identify response asymmetries in single-item measures of subjective well-being. An application to data from the German Socio-Economic Panel for 1984-2004 shows that income has only a minor effect on positive subjective well-being but a large effect on negative well-being.