So say you have a honeydew and a cantaloupe in your hands and I say hey gimme that melon . Which do you hand me ? <| sep |> Thank you for the reply . Okay , so what i was getting at was that this explanation the historical growth ratio differences could explain some of the currency shift in the long run . However , I ' m sure you ' re right that given the size of the shift and the short instantaneous period over which it occurred it seems unlikely that this explanation is even close to being sufficient . I assume that there is consensus about trade agreements being beneficial to the participating countries . Considering that the UK is leaving the EU it is safe to assume that they will have less free trade with the EU countries . That assumption implies that the economic growth forecasts should be lowered . Current situation UK is member of EU and benefits from the EU trade agreements . The thing that interests me is what these growth forecasts are based on . Are the lowered growth estimates based on assumption A or B ? Future situation A UK is not member of EU and does not benefit from the EU trade agreements at all . UK will not engage in other trade agreements . Future situation B UK is not member of EU and does benefit from the EU trade agreements to the same extent as before . UK is now not dependent on EU political support to secure trade agreements with other countries and therefore it is possible that they might benefit from other trade deals e . g . , with India . Of course , nobody knows if the UK will secure a new trade agreement with the EU or if they will be able to secure trade agreements with external parties that might offset the implications of the Brexit . However , I would think that there is at least some chance that it might be possible , but is that chance factored into the growth estimates ?