Some basic data from the WSJl [via Sean]:
For low-income workers, total pay and benefits rose by 41% from 1999 through 2006. But these workers’ wages increased only by 28%, barely outpacing inflation. The reason: Employer costs for these workers’ health costs nearly doubled, from 6.5% to 12.2% of compensation, and ate up money that could have gone toward salaries.
Now consider a worker who earns $250,000 or more a year. BLS data show that total compensation for these workers rose by 36% from 1999 through 2006. That’s actually less than for low-income workers. But the one-percenters’ health costs rose from just 4% of compensation in 1999 to only 4.3% in 2006.
It’s not that their health costs didn’t rise in dollars terms, it’s simply that health benefits are a much smaller part of their total pay and benefits. As a result, salaries for the one-percenters grew by 35%, a faster rate than for low-wage workers. The inequality of total compensation barely changed from 1999-2006, but rising health-care costs held back the growth of lower- and middle-class earnings.
There's much more in the original piece. Inequality likely has not increased over the years, and certainly has not increased as much as the strident redistributionists assert that it has.