> In March 2013, 94.8 percent of private businesses were single-pay-period businesses
meaning that most companies pay all workers on the same schedule. Therefore, if a company has any hourly workers that get paid more frequently than monthly, everyone salaried in the company is going to get put in the same pay schedule as well. All the orgs I've worked at either paid monthly uniformly or were part of that rare 5.2% that had different pay schedules, so I admit that my experience is an outlier here.
I assume this is because small businesses (and many employees) prefer a pay schedule that's aligned with their (often monthly ) bills for cash flow reasons. Whereas larger businesses prefer to keep payroll expenses from fluctuating a bit depending upon how many days are in a given month.
So the data suggests that being paid every two weeks is somewhat more common than monthly. (And, for larger businesses, biweekly is overwhelmingly the norm.)
[1] https://www.bls.gov/opub/btn/volume-3/how-frequently-do-priv...