This proposal covers three research strands at the intersection of innovation economics, economic history, and labour economics.In project A I will investigate how the number of entrepreneurs at the city level affects city growth. As the number of entrepreneurs in a city is likely to be endogenous I identify the causal effect of entrepreneurs using the exodus of Jewish entrepreneurs from German cities during the Nazi era. As different German cities were affected to varying extents by the exodus of Jewish entrepreneurs I can investigate how entrepreneurs affect local GDP and employment in the long-run. Furthermore, I will analyse which types of entrepreneurs matter (e.g. bankers versus manufacturers) because different cities lost Jewish entrepreneurs in different professions.In project B we will analyse how increases in the availability of secondary schools in Germany affect the number of talented people (such as scientists, parliamentarians or entrepreneurs) who originate from certain cities. To analyse the causal effect of secondary school availability we study large expansions in the number of schools in Germany that lowered the cost of attending an academic-track school for children in some locations, in particular for students in rural areas. Furthermore, we will investigate how the school curriculum and how single-sex versus mixed-sex education affect the production of talent.In project C we investigate the role of open science for the accumulation of knowledge. To investigate the causal effect of open science on the productivity of scientists we will investigate the exclusion of scientists from the losing Central Powers (e.g. Germany) from the international scientific community after WWI. As the exclusion affected scientists in different scientific fields and countries very differently we can identify the role of open science for the number of published articles by a certain scientist and how quickly she cites important work by foreign scientists.