Robert Putnam

For some time now, agreement has seemed near-universal that there is a growing chasm between those with great wealth in this country and the rest of the population. That recognition has even bridged our otherwise entrenched political divide, with both Republicans and Democrats tackling the problem, especially on the campaign trail. But despite the recent urgency, there are differences.

In this country, all children are supposed to have a shot at success — a chance to jump "from rags to riches" in one generation.

Even if riches remain out of reach, then the belief has been that every hard-working American should be able to go from poverty to the middle class.

On Tuesday, a book and a separate study are being released — both turning up evidence that the one-generation leap is getting harder to accomplish in an economy so tied to education, technological know-how and networking.