Watching this gripping animation (h/t Ezra Klein) that charts the spread of Wal-Marts across the country got me thinking. I felt like I was really watching the spread of wage stagnation across the country. I’m not suggesting there’s any clarity as to which came first — Wal-Mart or the grinding halt in middle-class wage growth. But Wal-Mart’s accelerated growth in the 1980s matches this chart on wage inequality nicely (note the bottom two lines).

It’s a pointless chicken-and-egg debate at a certain level. You can’t blame Sam Walton (much less Sebastian Kresge or James Sinegal) for the fact that discounters that thrive on downward price pressure represent the only means most Americans have of maintaining the illusion of a rising standard of living.

As it happens, that same lack of wage growth locked in the necessity of a food system that could produce calories for as little as possible. And it’s the fact that Americans’ real wages have been flat or falling during the Age of Wal-Mart that makes fixing the food system so implacably hard. Tom Philpott touched on this a little while back, identifying the Achilles Heel in any Pollan-esque remaking of the food system.

The ability to buy plenty of tasty calories on a low-wage salary actually lies at the heart of our economic system. For 30 years, our system has maintained corporate profits through a steady attack on wages. One of the major reasons workers have accepted stagnant wages is, I think, that food prices as a percentage of income have fallen steadily since the 1970s, a trend which went into reverse only last year. (The other is the ready availability of cheap consumer goods made by even-lower-paid workers in China).

Given that reality, it makes little sense to talk about transforming the food system and revaluing food without transforming the economic system and revaluing labor. Pollan never gets too far into those topics.

Any solution that involves the statement, “food needs to be more expensive” is going to be what the experts call a political non-starter. How to restart middle-class wage growth is, of course, the gajillion-dollar question — although I agree with Kevin Drum’s prescription: More Unions!

But short of that, we’re faced with maintaining agricultural subsidies in some form. Right now, all Americans effectively receive food stamps — it’s just that for most of us those payments go directly to corn and soy farmers. We can rail against the wastefulness of subsidies all we want. But given that the alternative is higher prices at the grocery store, I agree with Philpott that our focus should be on better rather than smaller subsidies. Exactly how we structure that isn’t at all clear, but unless Wal-Mart and its ilk start giving their employees big annual raises, the government is going to have to work to keep food, preferably real food, affordable.

Chart by Ezra Klein.