Berkeley, Calif.

THIS promises to be the worst Labor Day in the memory of most Americans. Organized labor is down to about 7 percent of the private work force. Members of non-organized labor — most of the rest of us — are unemployed, underemployed or underwater. The Labor Department reported on Friday that just 67,000 new private-sector jobs were created in August, while at least 125,000 are needed to keep up with the growth of the potential work force.

The national economy isn’t escaping the gravitational pull of the Great Recession. None of the standard booster rockets are working: near-zero short-term interest rates from the Fed, almost record-low borrowing costs in the bond market, a giant stimulus package and tax credits for small businesses that hire the long-term unemployed have all failed to do enough.

That’s because the real problem has to do with the structure of the economy, not the business cycle. No booster rocket can work unless consumers are able, at some point, to keep the economy moving on their own. But consumers no longer have the purchasing power to buy the goods and services they produce as workers; for some time now, their means haven’t kept up with what the growing economy could and should have been able to provide them.

This crisis began decades ago when a new wave of technology — things like satellite communications, container ships, computers and eventually the Internet — made it cheaper for American employers to use low-wage labor abroad or labor-replacing software here at home than to continue paying the typical worker a middle-class wage. Even though the American economy kept growing, hourly wages flattened. The median male worker earns less today, adjusted for inflation, than he did 30 years ago.