In table 13, regressions 8 to 10 sequentially delete the three productivity gap interaction terms that are not significant: the import to output ratio; the energy to capital ratio; and capital to labour ratio. The hypothesis that their coefficients are jointly zero cannot be rejected (F(3,221)=0.95 [P=0.41]). Regression 10 estimates a productivity gap coefficient of 0.038 and an R&D elasticity of 0.072. It contains three interaction terms that allow the effect of the productivity gap to differ with industries. It suggests that TFP growth has been faster, ceteris paribus, in those industries with lower ratios of non-production to total workers; with higher R&D capital to physical capital ratios; and higher export to output ratios. Regression 10 is the specification used later to calculate point elasticities for industry coefficients on the productivity gap.