Uncovering the Sources of Geographic Market Segmentation: Evidence from the

As a centre of excellence for innovative research on trade policy and its inclusiveness, we aim to equip the UK with the capability to formulate and implement a trade policy tailored to the needs of the whole of the UK, while recognising the importance of the multilateral trading system and the UK’s role within it. [...] In related work, Head & Mayer (2021) combines regional trade data for the EU and the US to compare the evolution of trade barriers in the US and the EU. [...] In the US, the difference in product availability differences is only 11% and 12% at the variety level and 4% and 9% at the firm level, depending on the measure. [...] Alongside the estimates, we provide the average value of the left-hand variable for domestic regions under “Domestic”, the number of observations and the R2 of the regression after partialling out the fixed effects. [...] While the sign of the differences in the outcomes is undetermined, the size of the differences remains determined, and so we will compare the absolute value of the differences.