I think it's easier to buy local in a smaller country too. Living in the UK, I suspect that 80% of my caloric intake comes from things grown within ~500 miles of me (and nearly 100% of the meat I eat), and I don't make great attempts to shop locally (but I do try a bit). When I'm in the US, lots of my food comes from the US and Canada, but that's a much larger geographical market. There's simply not much differentiation between something that comes from Vermont or Oregon. You might not even be able to tell by looking at a label. Whereas when you live in a small country, you can see "Produced in UK" or another nearby country fairly trivially.