The economy is booming. The stock market is frothy. Corporations are earning record profits. Yet workers are getting minuscule raises that don’t make up for the rising cost of living.

What gives?

To understand how this disparity came to be, consider the plight of long-distance truck drivers. They spend weeks away from home, crisscrossing the country to keep store shelves stocked and the economy humming. The trucking industry complains it can’t find enough drivers. And yet the value of drivers’ paychecks just keeps falling over time.

The 1.7 million heavy and tractor-trailer truck drivers in the United States earned an average of $44,500 last year, according to government data. That’s little changed in inflation-adjusted terms over the past several years. Over the past several decades, inflation-adjusted driver pay has fallen sharply. The 1980 census found that the average male driver — virtually all drivers at the time were men — earned roughly $17,400 in 1979, or about $55,500 in 2017 dollars . That pay drop has coincided with drivers working longer hours — 60- to 80-hour weeks are common, drivers and researchers say — because they spend many more idle hours than they used to at warehouses and stores waiting to pick up cargo and make deliveries, time that typically goes unpaid.

Many truck drivers are paid on a per-mile basis, which means that some of them earn less than the federal minimum wage of $7.25 an hour. The economics of trucking can be bleaker still for drivers who are classified as independent contractors. Some even wind up owing trucking companies money because a truck lease, insurance, fuel and other expenses can add up to more than their per-mile reimbursement rate, a phenomenon that Steve Viscelli, a sociologist at the University of Pennsylvania, detailed in his 2016 book “The Big Rig: Trucking and the Decline of the American Dream.”