This thesis consists of four self-contained essays on the topic of entrepreneurship. [Essay I] uses a unique and detailed Swedish dataset to explore firm, regional, and industry determinants that stimulate spin-offs using the choice of the individuals as the level of analysis. The most important results are that the size of the region and of the local entrepreneurial culture (the relative number of SMEs) has a positive effect on the propensity of the individual to set up a new venture corroborating the results of past firm- and regional-level studies. Industrial specialization is shown to have a positive impact on spin-offs, albeit only in high-tech manufacturing and in knowledge intensive business service sectors. Moreover, using an entrop...