The Spatial-Temporal Effects of Knowledge Spillovers and R&D Investment on Regional Agricultural Productivity: An Empirical Analysis Based on Province-level Panel Data from China

There is a broad consensus that R&D investment serves as a catalyst for technological advancement. However, the impact of R&D investment on Total Factor Productivity (TFP) varies significantly across research entities, particularly for agricultural Total Factor Productivity (ATFP), where the pronounced spatial spillover effects of knowledge—stemming from agriculture's strong geographical characteristics—complicate R&D's influence on ATFP. This study employs per capita R&D investment across different research entities, which reflects both capital and personnel inputs while distinguishing among entities to assess their temporal and spatial impacts on agricultural productivity. Using provincial panel data (1998–2022) and a progressive analytical approach, static and dynamic spatial econometric models are applied. Considering the heterogeneity of agricultural geographical production conditions and economic conditions, a novel agricultural production geography-based weight matrix is constructed. The results reveal that, statically, Research and Development Institutions (RDI) and Higher Education (HE) show strong direct effects but lack spatial externalities, instead exerting crowding-out effects on ATFP. Dynamically, HE exhibits initial inhibitory and subsequent promoting effects on ATFP, while RDI demonstrate strong negative externalities in the long term. It uncovers the unique impact pathways of R&D investment on ATFP, offering insights for optimizing regional innovation resource distribution. It highlights the need for tailored support policies suited to distinct research institutions, stresses the significance of temporal-spatial coordination in R&D investment, and calls for strengthening cross-regional knowledge-sharing mechanisms to fully realize R&D investment's potential in boosting agricultural innovation.