This paper provides a minimalist derivation of the gravity equation and uses it to identify three common errors in the literature, what we call the gold, silver and bronze medal errors. The paper provides estimates of the size of the biases taking the currency union trade effect as an example....

Based on the recent trade models of the Heterogeneous Firms Trade (HFT) model and the Quality Heterogeneous Firms Trade (QHFT) model, we classify export goods (at the HS 6-digit level of disaggregation) by quality and price competition. We find a high proportions of quality-competition goods for...