The simplest Zipfian distribution is a “1/f function”. Given a set of Zipfian distributed frequencies, sorted from most common to least common, the second most common frequency will occur ½ as often as the first. The third most common frequency will occur 1/3 as often as the first. The nth most common frequency will occur 1/n as often as the first.

Many fields use Zipf’s “Theory of least effort” including transport economics.