This paper explores a newly-available panel data set merging balance sheet and international trade transaction data for Belgium. Both imports and exports appear to be highly concentrated among few firms and seem to have become more so over time. Focusing on manufacturing, we find that facts...

We develop a new econometric framework that simultaneously allows recovering heterogeneity in demand, TFP and markups across firms while leaving the correlation among the three unrestricted. We do this by systematically exploiting assumptions that are implicit in previous firm-level productivity...