The Illinois Policy Institute, a Chicago-based conservative think tank, has recently devoted considerable energy to trying to prove that Illinois state worker pay is way out of line with private sector compensation. This week, they released a new memo that adds more fuel to the fire.

The Institute's latest "Spotlight on Spending" document compares state payroll data (catalogued on their own transparency website) with stats from the Bureau of Labor Statistics and finds that some state government workers receive average annual wages that are higher than the average statewide wage estimates for the same position. For example, the average welder in Illinois takes home $35,590 annually. If employed by the state, that figure jumps to $61,833 per year.

But while the data they present is technically accurate, they still have no grounds to assert that public sector wages "unnecessarily burden" the people who pay state government salaries: the taxpayers."

For starters, the "Spotlight" document analyzes only 17 professions that together account for less than one percent of the total state workforce.  By our calculation, revising public sector pay for those occupations to the private sector level would save the state roughly $19 million.  Quite a "burden" ...

By highlighting such a narrow subsection of the public workforce, the Institute also fails to take into account the wages of the bulk of state employees, many of whom are highly-educated and have no real equivalent in the private sector. Previous studies have shown that while low-earning occupations tend to earn more in the public sector, higher-earning professionals generally make less when working for the government. Indeed, a recent study by University of Wisconsin-Milwaukee professors Keith Bender and John Heywood found that local and state employees often make 15 percent less than their private sector counterparts. A quick (and by no means comprehensive) glance through the same databases the Institute uses lends credence to that thesis. Librarians ($58,890 vs. $53,043), paralegals ($52,330 vs. $43,340), photographers ($48,460 vs. $46,534) and dentists ($149,840 vs. $92,492) all make less if employed by the state of Illinois.

But why are those low-earning occupations compensated better within the private sector? Probably because union density is higher among government workers. While the Institute argues that the state's high unionization rate puts government at a competitive disadvantage and unfairly burdens the typical taxpayer, we take the opposite view. Even in a recession, why should the average janitor in Illinois make just $25,510 annually? At that rate, she can't afford fair market rent for a two-bedroom apartment in Illinois much less save for her child's college tuition or pay private health insurance premiums. Unions raise the floor on wages and safety issues for both their members and for the broader workforce.

Last month, Comptroller Dan Hynes told WTTW's Elizabeth Brackett that conservatives are using public employees  as "the scapegoat for these budget problems." The Insitute's new memo is just the latest example of that trend.

(Full disclosure: The SEIU Illinois State Council, which represents some public employees, sponsors this website.)