The U.S. Office of Management and Budget (OMB) has maintained the urban core population cutoff of a central county of a Metropolitan Statistical Area from 1950 through 2010 at 50,000 despite the U.S. population more than doubling over that time. This article uses a simple application of demand threshold techniques to measure evolution in the distribution of business establishments between 1980 and 2016 across core-based statistical areas. Extrapolating to 1950 and 2020, these techniques suggest a new population cutoff of 100,000, which is exactly consistent with a 2021 proposed rule change by the OMB. Given changing functional relationships between urban cores and rural peripheries, OMB's simple cutoff delineations may need to be re-evaluated; but in the absence of such a change {and with the goal of maintaining the original goal of these metropolitan cutoffs {this simple application of demand thresholds indicates OMB's proposal is sensible.