let me put it another way. We import more from England than they import from us - by a country mile. If we left the union we'd either be pegged to Sterling and would therefore be subject to spend decisions made by Westminster, or we'd be subject to tariffs, customs and currency fluctuations. Either way we'd be comparable with Chad within a generation.
given the lackwits in the Senedd couldn't make the decision re the M4 relief road, it does bode well for full political freedom.