... 224 firms: 70 in CHEM, 77 in COMP, and 77 in ELEC. The sampling period for the computation of TRA(i, j, t),INT(i, j, t) and TER(i, j, t) runs from 1976 to 1997. Including non-US firms in the sampleis ... ariables included in Model 1, patent counts and R&D expen-ditures enter the regression in Model 2. In Model 3, the three measuresof knowledge spillovers, namely, intraindustry, internal and interindustryspillov ... for intra- and inter-industry spillovers are positive and significant. In particular, the facev alues of the estimates suggest that interindustry spillovers have a strongerimpact than intraindustry...