This study contributes to existing literature on firmsโ innovative activity examining the relationship
between the R&D rivalry and spillovers at the firm level. In particular, we present an empirical analysis
in United States, Japan and Europe based upon a new dataset composed of 879 worldwide R&Dintensive
firms. In order to identify the technological proximity, we use the Jaffe industry weight
matrix, based on the construction of technological vectors for each firm, where its patents are
distributed across technology classes, in such a way that we compute knowledge spillovers. Opportune
econometric techniques, which deal with both firmโs unobserved heterogeneity and weak exogeneity of
the explanatory variables, are implemented. In order to test the robustness of our results, we introduce
also the combined spatial-autoregressive model with autoregressive disturbances and additional
endogenous variables. The empirical results are differentiated across countries, and suggest that the spatial effects are statistically significant