A review of 173 cities across the country shows where five of Connecticut’s largest cities stand according to one measure of pension cost.

New Haven ranks 27th and spent 10.2 percent of revenue annually on pensions, according to a study by the Center for Retirement Research at Boston College. The average across the sample is 7.9 percent, meaning New Haven has an above-average pension cost.

Newly-elected New Haven Mayor Toni Harp, a Democrat and state senator, said during the campaign she supports pension reform.

Measuring pension costs as a share of revenue can shed light on how expensive a city’s pensions are. However, it is only one measure. If one city taxes more aggressively than another – or uses more aggressive actuarial assumptions – it could appear to be lower-cost yet actually provide more expensive benefits.

How much a city pays for pensions today is also a function of how much it failed to pay in the past.

Chicago and Little Rock, Arkansas, lead the list spending 17 and 17.6 percent of revenue on pensions.

At the other end of the spectrum, Greenwich ranked 163rd and spent only 2.2 percent on pensions. Hartford (143) and New Britain (139) also had below-average costs, 3.6 and 3.8 percent, respectively. Bridgeport spends slightly more than average, 8.6 percent, and ranks 43rd.

The center researchers use the costs as determined by actuaries rather than what cities actually pay to measure pension costs. A study by the Census Bureau using actual payments puts the average at 5.6 percent because many cities underfund their pension systems.

Two Connecticut cities in the study send some of their pension contributions to state-run plans, Bridgeport, about one-fifth, and New Britain, more than two-thirds.