Does trade policy only have a small impact on trade flows? Interwar evidence

I have been working for a number of years on interwar trade policy, trying to see if using more fine-grained data will alter the consensus view that 1930s protectionism didn’t matter much for trade flows, in the context of everything else that was going on at the time. It is time-consuming work, but we are beginning to produce some results now, the first of which are previewed here. And I suppose that one upside of the time it has taken us to put the dataset together is that, in the meantime, Brexit intervened, which will hopefully increase interest in quantitative studies of trade policy!