Back in 1999, near the dizzying height of the dot.com boom, no executive in Corporate America personified the soaring pay packages of America’s CEOs more than Jack Welch, the chief exec at General Electric. Welch took home $75 million that year.

What explained the enormity of that compensation? Welch didn’t claim any genius on his part. He credited his success, instead, to the genius of the free market.

“Is my salary too high?” mused Welch. “Somebody else will have to decide that, but this is a competitive marketplace.”

Translation: “I deserve every penny. The market says so.”

Top U.S. corporate execs today, on average, are doing even better than top execs in Welch’s heyday. In 1999, notes a just-released new report from the Economic Policy Institute, CEOs at the nation’s 350 biggest corporations pocketed 248 times the pay of average workers in their industries. Top execs last year averaged 312 times more.

What explains this growing generosity to America’s top corporate chiefs? Today’s apologists for over-the-top CEO compensation, like Jack Welch a generation ago, point to the market.

One leading critic of these apologists, the Dutch management scientist Manfred Kets de Vries, neatly summed up this market world view earlier this year: Big CEO pay packages “reflect market demands for a CEO’s unique skills and contribution to the bottom line.” Mega-million executive paychecks “merely represent the market forces of supply and demand.”