In recent decades, the U.S. has been globalizing its economy, by cutting tariffs and shipping manufacturing jobs to China, and has been globalizing its population by importing tens of millions of poorly-educated Hispanics with IQs around the global average of 90. Notice the problem? People with an average IQ of 90 and a decent work ethic make okay assembly line workers. They don't do well, however, in a knowledge-based post-industrial economy. If we had wanted to have tens of millions more Hispanics, with their blue-collar capabilities, then we should have kept up the tariffs so there would be decent-paying factory jobs for them. Or If we had wanted to have a post-industrial "symbolic manipulation" economy, then we should have kept out the flood of people whose children grow up to have low NAEP scores. (A recent study by sociologists with the UCLA Chicano Studies Center found that only 6% of fourth-generation Mexican-Americans — i.e., people whose grandparents were born in America — had college degrees.) You can successfully globalize your economy or your population, but not both. We did both, so we ended up with fewer factory jobs but lots more people best suited to work in factories. Since the assembly line jobs weren't there, lots of them went into construction instead, temporarily helping lower the cost of building or improving houses, houses that we weren't making enough valuable goods to actually pay for.