The key to increasing upward mobility is expanding vocabulary.

E D Hirsch:

A number of notable recent books, including Joseph Stiglitz’s The Price of Inequality and Timothy Noah’s The Great Divergence, lay out in disheartening detail the growing inequality of income and opportunity in the United States, along with the decline of the middle class. The aristocracy of family so deplored by Jefferson seems upon us; the counter-aristocracy of merit that long defined America as the land of opportunity has receded.
These writers emphasize global, technological, and sociopolitical trends in their analyses. But we should factor in another cause of receding economic equality: the decline of educational opportunity. There’s a well-established correlation between a college degree and economic benefit. And for guidance on what helps students finish college and earn more income, we should consider the SAT, whose power to predict graduation rates is well documented. The way to score well on the SAT–at least on the verbal SAT–is to have a large vocabulary. As the eminent psychologist John Carroll once observed, the verbal SAT is essentially a vocabulary test.