[7] However, it has been argued that it is problematic to define cities through their fairly arbitrary legal boundaries (the places method treats Cambridge and Boston, Massachusetts, as two separate units).
A clustering method to construct cities from the bottom up by clustering populated areas obtained from high-resolution data finds a power-law distribution of city size consistent with Zipf's law in almost the entire range of sizes.
A new method based on individual street nodes for the clustering process leads to the concept of natural cities.
[11] The Weibull PDF can appear essentially log-log linear over orders of magnitude ranging from zero, while eventually falling off at unreasonably large outcome sizes.
In the study of the firms (business), the scholars do not agree that the foundation and the outcome of Gibrat's law are empirically correct.