There's a going joke in private industry which I've heard originated at one of my former employers. It goes that the CEO was asked how many people worked at the CYZ corp. His answer was "About half of them."
When we get to government, the percentage is nowhere near as good with evidence in this gem at National Review suggesting the percentage of useful workers might be as low as 10%. Kevin Williamson is inclined to see the other 90% as the descendants of protection racket thugs now gone "legit" for certain definitions of the word legit. He suggests that beyond police, firefighters and educators, the rest of government provides little in the way of public goods.
His point of view is valid enough but...
In most communities there isn't much actual crime, thus there is a need for only a small force of police. OTOH if you have a larger police force than you actually need, the force can not only take care of such crime as may happen, it can in its spare time, raise enough money to support itself in a fairly comfortable style.
The public works department serves a useful purpose in that it maintains the roads, filling the potholes, keeping the streetlights on and in their spare time, hanging the Christmas lights. In some places it's also a place to put the mentally challenged offspring of city aldermen.
Educators provide a useful service insofar as they actually educate the children but to my observation when you give them a monopoly, the quality of that service tends to fall off rapidly. Cutting them by 50% and opening the district up to charter schools has a salutary effect on the kids test scores.
Click the link and read the story, it's well worth the time.