Michigan\'s public universities should revise sabbaticals and other rules that give professors excessive free time supported by tax dollars and tuition. Requiring more attention to teaching makes sense in a time of skyrocketing tuition and tough state budgets. As money gets tight, perks should dwindle -- a common-sense principle now being applied in private industry. \"Sabbatical\" is an academic term for taking a paid time off to do pretty much what you want. Theoretically, the time is used for research. But many top professors already teach fewer than 15 hours a week and have much of the summer off as well. That\'s plenty of time to catch up on advances in their field and add to the knowledge base. Experts in other professions, including engineering, medicine and business, don\'t need months off to be efficient or productive. In school year 2004-05, more than 550 Michigan professors were paid for leaves. The tab was about $23 million in salaries, $8 million in benefits, not including paying instructors to fill in for absent professors. The figure is not large given the total spending for higher education. But it comes after many universities jacked up tuition at a double-digit pace. The schools are willing to make students sacrifice by paying more money, but they don\'t require professors to carry a bigger teaching burden.