This thesis uses a panel of Swedish counties over the years 1976-2007 to investigate the relationship between suicide and a range of socio-economic determinants. Moreover, the thesis is combining sociology and economics in order to understand the part of suicide that can be considered as rational. In addition, suicide is studied separately for total, male and female suicide rates. Contrary to prior research in the field of suicide, this study formally tests for gender differences. Applying a fixed effect model, we managed to uncover a statistically significant gender difference for female labor force participation relation to suicide. When applying fixed effect models most of our results were in accordance with the socio-economic theory of suicide. We found a significant u-shaped relationship between suicide and the level of alcohol sales (consumption). We also found a statistically significant positive relationship between the total suicide rate and female labor force participation. Moreover, we found that higher population density significantly leads to fewer suicides in the total and male model. Furthermore, we found that unemployment increases the male suicide rate. In some cases, however our results contradicted the theory. Our results give evidence that divorce has a negative and significant effect on total and male suicide rate. These findings are not only violating the theoretical framework but previous research as well. We can thus conclude that the socio-economic theory of suicide, in most cases, assistances us to understand suicide.