Economists Jayson Lusk and F. Bailey Norwood, in their essay The Locavore's Dilemma: Why Pineapples Shouldn't Be Grown in North Dakota, provide a perspective on the whole idea of locally grown food and why the economics of such an idea is not a reality that can occur.
Local food is generally more expensive than non-local food of the same quality. If that were not so, there would be no need to exhort people to 'buy local.'
Of note are the examples Lusk and Norwood provide to highlight the flaws in the ideas of "Local Consumption + Consumption of Imports = Income from Local Sales + Income from Exports".
[Editor's note, yes we know Mount Rushmore is in South Dakota, but the idea of a pineapple on a president's head was entertaining.]