How R&D grant size affects innovation in small firms
利用巴西PIPE项目1999-2019年企业面板数据，发现获得研发资助能增加小企业3年内专利申请，且资助规模与创新效果呈倒U型关系。
Abstract Public R&D grants are widely used to support innovation in small- and medium-sized enterprises (SMEs), which often face financial and managerial constraints. This paper examines how grant size affects SME innovative performance using evidence from PIPE, a long-running program in São Paulo, Brazil. Using firm-level panel data (1999–2019), we compare funded and non-funded applicants from the same calls using a doubly robust Difference-in-Differences estimator and an event-study design. We then assess treatment intensity through a dose–response framework. Results show that receiving a grant increases patenting within 3 years, with no evidence of differential pre-treatment trends. Dose–response estimates reveal a non-linear relationship: marginal returns rise with grant size up to an intermediate range and decline at higher levels of support. The findings highlight the importance of accounting for treatment intensity in the evaluation of SME-oriented R&D support programs.