We consider a semi endogenous R&D growth model with international trade, firm heterogeneity, and local knowledge spillover in a closed economy and international knowledge spillover in a symmetric two country economy. We show that by opening trade R&D difficulty (the number of varieties produced)...

We consider a semi endogenous R&D growth model with international trade, firm heterogeneity, and local knowledge spillover in a closed economy and international knowledge spillover in a symmetric two country economy. We show that by opening trade R&D difficulty (the number of varieties produced)...