This paper proposes a new distinction between two types of spin-offs, which is based on the events triggering spin-off formation. Spin-offs induced by newly discovered opportunities are distinguished from necessity spin-offs organised to escape deteriorating job conditions. An empirical analysis of spin-offs in the German laser industry traces differences in the performance and determinants of the two spin-off types. Necessity spin-offs are important to limit the devaluation of individual human capital by the competitive market process.