To be a locavore, here are some topics you’d need to research:
Why. Local food is all about sustainability. Civilizations do collapse from time to time and our is not exempt. Our food system is based on petroleum. If that supply of petroleum is interrupted, either by running out or losing a war in the middle east then Iowa and California will stop shipping food like they used to. When I was discussing this with my son, he said, “I don’t want to talk about it–this is scary.” I think that is the crux of the problem when you see people on the internet reacting violently against the local food movement.
While Iowa and California have a comparative advantage at growing animal feed and vegetables respectively– this comparative advantage is unsustainable. But the economy gives consumers only one signal for efficiency and sustainability: price. If given the choice between subscribing to a supply of food that will be initially cheap and then disappear forever and a supply of food that is expensive and last forever it would be false economy to rely on the former. The problem is that price gives us no signals on the sustainability of supply.
Rational humans do care about sustainability–in fact many of the moral arguments for saving and investment are based on sustainability arguments. Hence, it is rational to favor a sustainable food supply over a unsustainable food supply even if it is more expensive.
Geography. Measuring distance is tricky. Personally, I think anything shipped over water (such as shipping wine from Spain to DC), should be considered more local than shipping it over land (such as shipping wine from California to DC). Food on major transit routes should be considered more local than food that is local but has significant geographic barriers (such as mountains or sparse roads). At the very least, one should learn the names of the counties. Food is also normally shipped through hub and spoke shipping centers, so to ship food from say 1 block away from your grocery store to the grocery store, it will still go through a distribution center, possibly hundreds of miles away.
CSA and PYO. That means Community Supported Agriculture and Pick Your Own respectively. CSA gets the transaction costs for farmer’s market food down to an affordable amount. Some of the economies of scale lost by using a local producer are regained by increasing the transaction size. Pick Your Own shifts the labor onto the consumer to make labor intensive products like raspberries affordable.
Comparative efficiency of local goods versus distant ones. If you are living in Murmansk, Russia, growing oranges locally is just as unsustainable as shipping them from around the world. Crops that are local block busters are likely to be efficient, for example peanuts in Virginia.
Cooking. Most people cook about a dozen recipes at most, over and over and over. Changing to a diet that uses local foods means tracking down some new blockbuster recipes that use local foods.
Locally grown vs locally processed. If you are eating locally raised dairy or eggs that ate food that was shipped around the world, how local is that? Processing is where most of the value is added to the raw materials. It isn’t clear where the best place to process something is, we do know that factories are most efficient when they are very big. Since petroleum factories are not all that sustainable, we might as well process foods where ever it is most efficient and prices should accurately reflect that. If it is cheaper to ship coffee from Kenya to New York for processing then ship it to DC, then that is what we should do. Thinking about coffee processed in Virginia is asking the wrong questions. The better question is how to make coffee out of locally grown chicory and tea.
Countries, States, Counties. Hawaiian coffee is no more local than Kenyan, don’t be fooled by the fact that you live in the same country as the former. With distribution centers, food bought at stores probably is all just as local (travelled just as far), for your entire quadrant of North America.
Distant Organic vs Local Organic. Consumers have to send a signal to producers somehow. Just like I wouldn’t want to buy products made with slave labor, I don’t want to buy products that involve factory farms (hyperdense livestock feedlots), GMO (it’s about intellectual property laws more than health risks), and I do want to buy products that involve fair trade, organic production, etc.