(The paper can be downloaded from: https://www.nber.org/system/files/working_papers/w30840/w30840.pdf)
Pruisken found that along with these factors, there were four urban paths to megachurch establishment, the most frequent one consisting of having a large presence of evangelicals and Christian fundamentalists (as in Dallas, Atlanta, and Houston), followed by population growth and a large presence of Hispanics (in Miami, Dallas, Houston, Los Angeles, San Diego, and Phoenix). At least in the U.S., Pruisken found that megachurches also grow in cities that are characterized by a high degree of cultural pluralism, Seattle being the main example. In this third path, there is the conjunction of tolerant educated groups and evangelical or mainline Protestant groups, as well as population growth. The fourth and weakest path for the success of megachurches is in areas with a tolerance of homosexuality and mainline Protestants, often consisting of black and mainline Protestant megachurches (such as in Washington, DC, Baltimore, and Minneapolis-St. Paul). But this path is also marked by competitive pressure from secular forces and lower population growth.
(Sociological Forum, https://onlinelibrary.wiley.com/journal/15737861)
(Society, https://www.springer.com/journal/12115)