There is actually a function in the game's code called something like Get_Fudged_Population that determines what will display as your city's population. If you look at the detail screen and add the workers, shoppers, and students, that is the *actual* population of your city.
They fudge the numbers do to trying an abstract approach. The problem with that is they only do it to the population. They need to fudge the numbers on employment. If they can pack in 370k in such a small area. Why does the commercial jobs number so few.
Also, They should put the sims thought pattern to be to take a job they area actually qualified for. I have problems with them saying they need jobs, but there is job openings for their educational level. It really is annoying to say the least.