One evening in April 2010, in the middle of my time as mayor of Kansas City, Mo., some 750 to 1,000 young people descended on the city’s upscale shopping district, Country Club Plaza. There were assaults, property damage, and a lot of frightened customers and upset business owners. My staff told me that what had occurred was a flash mob fueled by social media and that one had happened a couple of weeks earlier in Philadelphia. I immediately called Philadelphia’s then-mayor, Michael Nutter. He gave me solid advice and worked with me to set up a meeting between our respective staffs the following day.

Now Nutter has published a book filled with blunt advice for mayors, would-be mayors and other city leaders. Mayor: The Best Job in Politics is an insightful look at both campaigning and serving. It’s also a brisk, fun read, even in describing fiscal challenges like those his city faced in the Great Recession. He writes, “Being in my first year and not knowing all the things I needed to know, I didn’t realize that the last call you ever want to get is the chief of staff and the finance director saying they want to talk to you and it’s important. … They are not coming to tell you that they found a billion dollars in the sofa.”

Nutter’s book is, however, about only one kind of city. Philadelphia is what H. George Frederickson, Gary Alan Johnson and Curtis H. Wood, in their 2004 book The Adapted City, call a “political city,” one in which the mayor is both political and administrative leader. The authors estimate that about 16 percent of American cities fit this model. At the other end is what they term “the administrative city.” In these, which constitute about 14 percent, the mayor is selected by the city council from among its members and administrative authority is held by a council-appointed city manager. The remaining cities employ some variation of one or the other.

It surprises me that with the rise of interest in cities in recent years -- as evidenced by programs ranging from Bloomberg Philanthropies’ What Works Cities to the Rockefeller Foundation’s 100 Resilient Cities to the MetroLab Network that pairs local governments with academia -- no one seems to be considering these differences in governing structure. Yet Nikuyah Walker, recently selected by her Charlottesville, Va., City Council colleagues as the city’s first black female mayor, has significantly different power and authority than Nutter had in Philadelphia.

This is not an argument for one form of government or another, but that the current focus on cities, while welcome, misses the important fact that the structure and authority of the mayor’s office differs vastly from city to city. The subtitle of Nutter’s book calls being mayor “the best job in politics.” It is also the least understood. We need more research on what works best.