(FORTUNE Magazine) – ''You could call this the Marie Antoinette school of management,'' says leading compensation expert Graef S. Crystal. The Berkeley professor has discovered a growing gap between the pay of CEOs with long tenure and hourly workers. Crystal calculates that veteran chiefs typically earn 130 times the average U.S. factory worker's annual pay of $21,735, vs. 34 times as much 14 years ago. Hefty increases in long-term incentives account for much of the increase. They include stock options and restricted stock, shares the CEO receives free but may not sell during a specified period. In the past three years these incentives have accounted for 57% of the total pay package of the veteran CEOs studied. The median package averaged $2.8 million annually. Fourteen years ago noncash compensation was only 13%. For consistency, Crystal restricted his study to CEOs who had held their jobs for at least 17 years. Darwin Smith at Kimberly-Clark, who earns 59 times a factory worker's wage, ranked lowest among the nine CEOs studied. At the top was Richard Eamer of National Medical Enterprises, a hospital management firm, whose package was worth an average of $13,585,000 a year between 1987 and 1989. In ancient times Plato suggested that the highest-paid person in a community should not make more than five times the lowest-paid one. But then, few CEOs in Plato's time got megastock grants.