From the Wall Street Journal:
To sum up, Mr. Cowen believes that America is dividing itself in two. At the top will be 10% to 15% of high achievers, the “Tiger Mother” kids if you like, whose self-motivation and mastery of technology will allow them to roar away into the future. Then there will be everyone else, slouching into an underfunded future of lower economic expectations, shantytowns and an endless diet of beans. I’m not kidding about the beans.
Poor Americans, writes Mr. Cowen, will have to “reshape their tastes” and live more like Mexicans. “Don’t scoff at the beans,” he says.
In other words, sure, America had its centuries in the sun as a high wage / low cost of land country as Benjamin Franklin pointed out in the first immigration restrictionist essay. But now America will suffer the inevitable fate first described by the Mexican polymath Francisco Galtonez in his landmark 1869 book Hereditary Peonage: Regression to the Bean.
Or America could do something about cutting back on immigration, but that's unthinkable, so: Beans ahoy!