Agree completely with Jeff's analysis. Stuart has an interesting start to a position, though there is still quite a way to go. And causality in this situation is most certainly highly multivariate, so simple explanations will not capture a full understanding of the data trends.

Certainly both large and small farms can exist in the future, as every nation may choose different ways to incentivize one over the other (or choose not to incentivize at all, though it would be hard to imagine such a situation in a high-consuming nation). So the answer may be that neither large agriculture nor small holdings will dominate the other overall.

Certainly the suburbanization that has been taking place in the last 50 years can contribute to the ability of those homeowners to respond to high food prices with home gardens; indeed, quite a bit of food can be produced in an intensive gardening approach on a 1/4 acre. See the this Chicago suburbanite who is growing 97 apples trees on his 1/4 acre lawn.

See Garden Girl explain Urban Sustainable Gardening in this video.

And raised beds provide many times the output in the same amount of space that traditional gardens do.

This suburban apple farmer is a great example that, while it may remain impracticable for many people to achieve true food self-sufficiency at their present property, it is certainly possible for most people to take significant steps in that direction. Just a few more examples of people who are working on this transition as we speak: Farmlet (of Cryptogon fame), Mossback Farm, and Lichenology. I've also written about The Self-Sufficient Gourmand.

These examples don't specifically address the economic efficiency issue per se, but I think they do highlight that the ultimate goal of economic efficiency is to fulfill human needs--these people are all very bright and could easily be making six figures elsewhere if that was their sole desire. Instead, they seem to have realized that small-scale farming, while perhaps earning less money, fulfills their true needs far better than pure monetary analysis would suggest.

And while these gardens can absorb a bit of time, clever gardening practices (i.e., mulching, companion planting, etc) can greatly reduce the amount of time spent weeding, which is arguably the most time spent in the traditional home garden. And you'll be surprised how much you can squeeze in a yard;

I have a full time high tech job, though have a flock of 20 sheep, 45 fruit and nut trees in an edible landscape, and 18 raised beds (3'x12') in my home garden. While I obviously have more than a 1/4 acre, it shows that this does not have to be a full time job by any stretch of the imagination. It does get busy at spring planting time (or lambing time) but it is a fulfilling busy-ness that gives one a feeling of satisfaction and a sense of accomplishment. And the grocery bills are much, much lower than they used to be.

Even people living in apartments (with somewhat south-facing balconies) can grow some of their own food;

Looks like I'm a little late to the party, but thanks for the kind words, Jeff. Being mentioned in the same sentence as Kevin (farmlet) and Zane (lichenology)...I just hope I can live up to the expectations.

Keep up the good work

Thanks Will, nice to see someone enjoying his place like that, now if his neighbour to the left would grow carrots ,the neighbour to the right cabbage and the one behind beets they could invite Dmitry Orlov over for a bowl of Russian bostch and a slice of American apple pie. A bit of dill growing on the front drive would not go amiss.

one thing overlooked is the suburbs have a lot of basement space to grow food year round. my grandfather had a huge basement under his ranch home.

Rare basements, if any, in Texas.

What are going to grow? Mushrooms?

No silly, something financially remunerative. A brownie additive!