It’s been 17 years since a major city and county in Georgia voted to merge their governments.

Voters in Macon and Bibb County, making their fifth try since 1933, are hearing many of the same arguments for and against consolidation that have been heard in almost every other attempt in the state. The biggest point of debate is financial: Backers urge consolidation as a way to cut the cost of local government, while opponents say the pledge written into the proposed charter -- of cutting the governments’ combined budget by 20 percent over five years -- is unrealistic.

According to 2000 research by the Carl Vinson Institute of Government, that’s still an open question.

“Unfortunately, little hard data exist to support either of these two claims,” researchers wrote. “In fact, very few studies have examined the impact of city-county consolidation, and what little evidence does exist suggests that costs will actually increase in the short term.”

But government costs in general continue to rise, and in the case of Athens-Clarke County, at least, the increase after consolidation was slower than the increase seen in unmerged governments.

Athens and Clarke County hoped for, but did not mandate, savings from consolidation. And eight years after the fact, a study by Douglas Smith concluded that automatic assumptions of savings from a merger -- or even specific predictions -- weren’t tenable.

“It should not be stated that consolidation will save a certain amount of money because that cannot be known in advance,” said Smith, a former Athens-Clarke County employee who’s now assistant city manager of Delray Beach, Fla. “Real cost savings may not be realized for years.”

Only 38 consolidated governments exist nationwide, and seven of them are in Georgia, according to Carl Vinson Institute research. Between 2003 and 2008, there were mergers in four Georgia counties, but all were very small, with total populations less than 15,000, so the results were more akin to dissolving small-town governments.

Even among those cities and counties that succeeded, unification usually followed multiple failures. Macon-Bibb County rejected consolidation attempts in 1933, 1960, 1972 and 1976.

Current and former officials in Athens-Clarke County, Augusta-Richmond County and Columbus-Muscogee County all said that substantially cutting the size and cost of government in their communities couldn’t have been done without major cuts in government services and the number of public employees.

They emphasized that successful consolidation can’t come quickly. All three had much less time to set up new governments than the 17 months Macon-Bibb County would have under the current proposal.

“Merging two governments is an incredibly complex process,” Smith said. “Not all the problems can be predicted because each situation is different. The key is to get the employees to buy into the changes, to be adaptable and to be flexible.”

Gwen O’Looney, a member of the former Athens City Council and then countywide mayor for eight years, said it was vital to seek and heed input from average residents at every stage. In Athens-Clarke County, that participation has resulted in former opponents of consolidation telling visitors how well it’s worked out, she said.

“Over the long term, consolidation sold itself,” O’Looney said.