Downtown growth curves

This is a question on growth curves, geared to Chicago and its midwestern neighbors. It could just as easily be used on other cities & regions as well, due to its generic nature. Chicago is a huge major city, a city that has developed an incredible critical mass. Downtown Chicago's growth is based on its critical mass. Chicago's development is based on growth feeding on growth, on all the right things on the ground to make make further development profitable, by having a large population with large disposable income that again contributes to further business profitability. Its sheer size, importance, and economic might make a Navy Pier redevleopment, a Millennium Park, a Museum Campus possible. Then, take other midwestern cities: the ones that are established in creating an inviting, growing downtown (as is Mpls), the ones turning the corner out of the doldrums (StL, Det), the ones based on sheer promotionalism (Indy, Columbus)...throw in the others (Clev, Cincy, KC, Milw, etc.): will these cities, far smaller than Chicago, experience a growth curve downtown greater than Chicago because of turn arounds and their frankly smaller size magnifies growth -or- does Chicago's growth that feeds on existing critical mass accelerate more than the others due to the incredible magnet setting that has been created here? Exponentially, where will the growth cruve be steeper: in Chicago or in the other midwestern cities? And thus, in the process, does the gap between Chicago and the other cities get greater or less??????? (i.e. could a revitalized, reinvigorated St. Louis actually find itself in a worse positon vis-a-vis Chicago which somehow manages to widen the gap by ever more extraordinary growth?) I hope this makes sense as I really would like to know what you guys are thinking.>