Cambridge’s Richard Rossi isn’t the only city manager to come under scrutiny for a hefty salary.

City managers in Phoenix ($78,000 raise), Cincinnati ($20,000 raise), and San Antonio ($355,000 salary) have also raised eyebrows with their compensation.

Rossi doesn’t succeed his boss Robert Healy until this summer, but his recently approved salary of $330,000 has prompted some to ask if it’s too much.

Now, it’s not the first time the topic of the Cambridge city manager’s pay has faced criticism. Current manager Robert Healy earns even more – at $347,000.

Both salaries are triple the national average for what a city manager takes home nowadays, which is $110,000.

Such numbers – and those of other high-profile city managers around the country – might make you ask if they’re really worth the money.

In the case of Rossi, one thing to consider is the structure of government in Cambridge, said Wayland Town Administrator Frederic Turkington.

“The Cambridge salary is far and away the highest in the state and I would say that one of the reasons for that is that it is the largest, probably most complex urbanized environment in the state that has a city manager form of government,” Turkington said.

What exactly makes Cambridge so complex and different? If you follow the money, it might start with the two largest employers in Cambridge: Harvard University and MIT. Cambridge is the only city that can boast having not one, but two of the top 10 richest colleges in its backyard. MIT alone accounts for 12 percent of Cambridge’s tax revenue stream – making it the city’s largest taxpayer.

But let’s dig a little deeper. At $69,000, Cambridge’s median household income is around $16,000 to $17,000 more than the average incomes in Boston and the U.S.

Even more astounding: 73 percent of people in Cambridge over the age of 25 have a bachelor’s degree or higher. Statewide, the total is just under 39 percent.

And it’s same story when you compare degree holders in Cambridge to those in similar city manager cities such as Austin and San Jose. Managers in those cities are some of the highest paid in their governments, but still fall short of Rossi’s salary.

Turkingtion admits that Cambridge isn’t the norm for measuring the salaries of city managers.

“I think Cambridge is a little bit of an outlier," he said. "You certainly find examples of cities that have comparable salaries. I think if you factor in the cost of living differences between Massachusetts and Texas, it certainly would account for the $60,000 difference.”

If you look around, it’s hard to miss a government with a city manager. More than half of local governments in the U.S. have what’s called a council-manager government.

In most cases, the mayor is not elected and comes from among the city council. The city manager acts as a CEO who is tasked with running the day-to-day operations of a municipal government.

But Turkington, who is also president of the Massachusetts Municipal Management Association, says many times people mistake what he and other city managers actually do.

"People that come up to me in my personal life, you know, I tell them what I do for a living and they say, ‘is that like being the mayor?’" he said. "And I say, ‘Well, it’s more like being the school superintendent of every other town department.’"

In addition to Cambridge, Lowell and Worcester are two of the largest cities in Massachusetts with a manager-style government. Both cities lack Cambridge’s wealthy tax base, but their city managers are still well paid. In fact, they even make more than Boston mayor Tom Menino. Lowell’s city manager Bernard Lynch earns around $180,000 a year, while Worcester’s Michael O’Brien takes home over $184,000. Menino comes up not far behind with a salary of $175,000.

Go to Bridgewater, go to Randolph, go to Palmer, or anywhere around the state and it’s not hard to find other city managers or town administrators who make more than the national average of 110,000. But remember that Massachusetts is one of the top five or six states when it comes to median household income.

According to Bob O’Neill, who heads the ICMA, or the International City/County Managers Association, in Washington D.C., many possible reasons can account for differences in salary.

"A lot of things drive the salaries: where you are, what historically has been paid, what’s the cost of living in the area," O'Neill said. "Our offices are in Washington D.C. and the salaries for local appointed officials in Washington D.C. are greater than they are 150 miles from there and it’s purely a marketplace question."

O’Neill said that while the topic of salaries isn’t new, people are coming to the table with more sophisticated questions than in the past. And that type of discussion is a good thing to have, said Deidre Cummings, legislative director for consumer watchdog MASSPIRG.

"There is a salary, people have heard about it and now there’s a discussion going on about it," Cummings said. "And then those elected officials in that community will have to grapple with, ‘Is this what the taxpayers in Cambridge want or don’t want?’ So in a way it’s a good discussion happening."

At the same time, the city manager profession faces a potentially bigger problem than debates about salaries: it’s not getting any younger. ICMA research shows that 63 percent of managers it surveyed were 51 years old or older.

"I think it’s a reflection of our own society," O'Neill said. "I think we’re aging. A lot of the growth in municipal operations took place in the late '60s, early '70s, into the early '80s and you’re seeing that generation of people who were attracted to public service reaching the age of retirement or close to it."

And when it comes to diversity, the numbers are even smaller. From Charlotte to Forth Worth, to even Barnstable, only 20 percent of the managers surveyed nationwide were women. An even smaller share were people of color – less than 5 percent. Turkington said Massachusetts has made strides recruiting women into city manager positions, but still falls short finding minorities in suburbs and small towns.

"I will say the effort has been a little harder in the northeast because, as I noted, most of the communities are in urban settings where they would have talented, minority individuals in mid-management positions ready to probably evolve over the next five to 10 years into a management position, they still work in a city-managed form of government," Turkington said.

Among the largest cities in the U.S. with manager-council governments, there has been progress. Of the nine largest cities with such governments, seven have managers who are women or a minority.

O’Neill said in many places it’s not necessarily where more diverse candidates are located as it is them just knowing about the opportunities. But he adds that, in the end, like all politics, the decision to hire more women and minorities is local.

"You have to remind yourself that you can increase the numbers in the pipeline, but the final decision – who becomes the city manager, or the town administrator, or county manager – is a role of elected officials," he said.