The influence of grant renewal on research content: evidence from NIH-funded PIs

The continuity of research funding is a critical factor influencing scientific progress. Interruptions in funding can disrupt research activities, force researchers to shift their focus, and potentially hinder innovation. Grant renewal, which provides continued funding, is an increasingly important instrument in the research funding landscape. However, its impact on the research content remains underexplored. This study investigates how grant renewal affects the research content of Principal Investigators (PIs) funded by the National Institutes of Health (NIH), specifically examining their effects on three key dimensions of research content: switching probability, diversity, and novelty. To examine the effects of grant renewal on research content, we integrate funding data from NIH ExPORTER, textual data from PubMed and comprehensive publication and author information from SciSciNet. We measure these dimensions of research content using text-based indicators, as text-based methods offer a more nuanced understanding of the essence of research content. Potential selection bias is addressed using Propensity Score Matching (PSM) to create comparable groups of PIs based on grant renewal status following their first R01 grant’s initial duration. A Differences-in-Differences (DID) model then estimates the causal impact of grant renewal on research content. Our findings reveal that while grant renewal is associated with a lower probability of PIs switching research content and a reduction in the diversity of their research content, it also has a statistically significant positive effect on research novelty. These results suggest that while grant renewal narrows the thematic scope of PIs’ research, it fosters an environment conducive to focused innovation within a chosen area. This study highlights the potential of grant renewal to be an effective instrument for promoting impactful research by enabling PIs to pursue long-term research goals with continued funding support. The findings have significant implications for research funding policy, underscoring the importance of considering the effects of funding mechanisms not just on funding acquisition but also on the content and trajectory of scientific research.