After decades of debate over the merits and drawbacks of consolidating Lewiston and Auburn, the residents of Maine’s Twin Cities got their first peek last week at a draft charter that sketches out how a unified government would look. A referendum vote to merge the cities could come as soon as November.

So why merge? Gene Geiger of Lewiston, chair of the six-member volunteer joint charter commission, said a consolidated government would improve efficiency and delivery of municipal services, attract economic development and reduce the cost of governing.

“In concept, I believe this will be beneficial for taxpayers,” Geiger said. “But that has yet to be proven.”

Before the commission puts the charter before voters, its members have several issues to settle, including how the cities will deal with their debts, where the new government will be located and whether the merger will save taxpayers money.

To fill in these gaps, the commission hired New York-based consultant CGR to analyze the benefits and drawbacks of merging and provide the commission with options for combining government operations. Those findings won’t be available until later this year, but here are three things residents of the Twin Cities can expect as their cities consider marriage.

Mergers face long odds

No Maine municipalities have merged since 1922, when the towns of Dover and Foxcroft united as Dover-Foxcroft. Since then, several municipalities have actually split after secession efforts, including Long Island, which seceded from Portland in 1993, and Chebeague Island, which seceded from Cumberland in 2006.

By and large, few mergers get enough support to pass. Suzanne Leland, a public administration professor at the University of North Carolina at Charlotte, has studied more than 100 merger referenda that have been held since the 1970s, the majority of which failed.

“Only about 15 percent of consolidation referenda pass,” Leland said. “It is truly a rare event.”

Those odds don’t bode well for the prospects of a Lewiston-Auburn merger.

Not that those exploring the merger option need a reminder. Over the last 20 years, three different citizen commissions — in 1996, 2006 and 2009 — recommended Lewiston and Auburn merge and laid out the benefits in store if they followed through. City officials, however, largely ignored those recommendations.

The 2009 commission wrote in its final report that the prior merger efforts stalled in part because city councilors on either side of the Androscoggin River didn’t feel a sense of urgency, especially as they contended with more immediate matters, such as passing budgets. The commission also concluded that merger efforts failed to garner support because residents on both sides of the river feared they would lose autonomy and political control.

“[Mergers] are politically difficult to pass because they typically mean that two different governments have to be willing to give up their identities, accept the debts of the other governments, lay off workers if cost savings are promised, and the existing elected officials will have to run under the new unified government, which may make re-election more difficult,” Leland said.

They produce minimal savings

Many make the argument that merging municipal governments will yield significant savings for municipalities by reducing the ranks of administrators — having one police chief instead of two, for example, or one public works director, not two.

“Logic says if you can streamline redundancies and improve efficiency, there has to be savings there,” Geiger said. But Geiger is careful not to promise big savings and admits “we don’t know what savings there might be.”

In 2009, the citizen commission exploring a merger identified $2.6 million in potential savings over five years from consolidating administrative positions, police and public works departments. But the potential for those savings likely has dried up since 2009 as the cities have reduced staff and services already in response to shrinking budgets brought on by lower property values and reduced state aid, Lewiston City Administrator Edward Barrett said.

Over the last six years, Lewiston has eliminated 33 positions from its city staff and operated on a flat budget, Barrett said, which may leave little room to find savings through consolidation.

Even when a municipal merger nets savings for cities, it’s unlikely the savings will be great enough for taxpayers to notice.

In 2011, residents of Princeton Township and Princeton Borough, New Jersey, voted to merge their municipalities after more than five decades of debate. On Jan. 1, 2013, they became the town of Princeton. The united Princeton has realized about $3.9 million in annual savings, or 6 percent of its $60.9 million consolidated budget for 2015, according to Scott Sillars, chair of the consolidation finance committee.

“We lowered everyone’s tax bill in the first year by about half a penny,” Sillars said. “But that’s since flattened out.”

After its merger, Princeton leveled up the salaries of some municipal employees, such as police officers, to match the pay level of their higher-paid counterparts, which cost Princeton about $275,000, according to Sillars.

Lewiston and Auburn could face that same issue with not only the ranks of municipal employees but also with those who work in the cities’ schools. Lewiston spends about 36 percent of property tax revenue to fund K-12 education. In Auburn, education accounts for 38 percent of municipal spending. The joint charter commission hasn’t yet offered insight into what would happen with the cities’ respective schools after a merger, but school department changes will add to the complexity of merging two city governments.

For Princeton, school department consolidation wasn’t an issue because the township and borough already shared a school district.

A common vision leads the way

The prospective Lewiston-Auburn merger is about more than just saving tax dollars, though supporters say finding some savings will be necessary to broaden support among voters. A united Lewiston and Auburn can work together on business attraction and development and gain more political leverage in Augusta, Geiger said.

Nowadays, “we’re not pulling together as one entity. You have Auburn going left and Lewiston going right,” Geiger said. “But if you have one system, with one plan, everyone is pulling in one direction to support common goals.”

The key to a successful municipal merger is a unified vision on which city leaders and residents agree, according to a 2011 study by Leland and Kurt Thurmaier, a professor of public administration at Northern Illinois University.

Then, city leaders “must successfully convince voters that the existing political structure [is] inadequate to support and implement that vision and that the solution lies in consolidation,” Leland and Thurmaier wrote.

Without a shared vision, the merger can fall victim to distrust among the cities’ residents, giving rise to the fear that one or the other city will lose autonomy.

Before the two Princetons merged in 2013, four previous merger attempts failed at the ballot box for this very reason.

“There was a concern that the Borough would lose its voice if the two cities were combined … that the Township would subsume them,” Anton Lahnston, chair of the Princeton Joint Consolidation and Shared Services Commission, said. “So when it passed, it was a big vote of confidence.”