heterogeneous firms and costly trade. Growth originates from horizontal specialization and the steady state productivity growth rate … production. -- productivity ; entry costs ; heterogeneous firms ; trade liberalization …

investigate the relation between firms' trading activities (importing, exporting or both) and productivity. We find important self … correlated within firms, failing to control for the importing activity leads to overstated average productivity premia of … exporters. -- Trade openness ; Firms' Heterogeneity ; Productivity …