This paper analyses the factors that drive the total employment in the research sphere of publicly funded research and development (R&D) projects, focusing on the contribution of essential characteristics of a project design. The aim is to examine how the project budget, implementation duration, and induced private investment affect the level of research employment during project implementation. It is analyzed using project level microdata of 1,435 publicly funded R&D projects in the Attica Region implemented between 2007-2015. To conduct the empirical study, an econometric model of the log-linear was estimated with the use of the ordinary least squares (OLS), which is the standard error robust to heteroscedasticity to determine the existence of systematic relations between the characteristics of project and employment in the research sector. These empirical findings indicate that research employment is positively and significantly influenced by all the three explanatory variables. The larger project budgets correlate with larger research capacity that is related to a higher availability of resources and a broadening in the scope of research. The relation between induced private investment and employment also demonstrates a great positive status proving that the private funding supplements the public funding. Overall, the findings provide strong evidence of the existence of economies of scale in publicly funded R&D projects. The study contributes to the relevant literature by providing project-level information on the relationship between innovation policy design and employment outcomes and highlights the importance of design features and the role of private investment in shaping the demand for research human resources.