AMID the global economic turmoil and seesawing markets, millions of Americans have one overriding question: When will my pay increase arrive? The nation’s unemployment rate has fallen substantially since the end of the Great Recession, sliding to 5.1 percent from 10 percent in 2009, but wages haven’t accelerated upward, as many had expected.

In fact, the labor market is a lot softer than a 5.1 percent jobless rate would indicate. For one thing, the percentage of Americans who are working has fallen considerably since the recession began. This disappearance of several million workers — as labor force dropouts they are not factored into the jobless rate — has meant continued labor market weakness, which goes far to explain why wage increases remain so elusive. End of story, many economists say.

But work force experts assert that economists ignore many other factors that help explain America’s stubborn wage stagnation. Outsourcing, offshoring and imports exert a steady downward tug on wages. Labor unions have lost considerable muscle. Many employers have embraced pay-for-performance policies that often mean nice bonuses for the few instead of across-the-board raises for the many.

Peter Cappelli, a professor at the Wharton School of Business, noted, for instance, that many retailers give managers bonuses based on whether they keep their labor budgets below a designated ceiling. “They’re punished to the extent they go over those budgets,” Professor Cappelli said. “If you’re a local manager and you’re thinking, ‘Should we bump up wages,’ it could really hit your bonus. Companies have done this in order to increase the incentive to hang tough on budgets, and it works.”