How do I “proportion” thee? Let me count the ways:
• “Checks dated by April 30 will receive a special, proportional match.”
• “A proportionate number of teaching or administrative positions were not eliminated.”
• “Future resource additions will consist of a proportionable mix of new construction, demand side management and purchased power.”
• “They have computers that proportionalize things for you.”
All of those forms have the same intent, whether as an adjective or adverb (or verb): To show a relationship between a whole and a part—or “proportion.”
But they don’t all mean the same thing … or maybe they do.
While most dictionaries list “proportional” and “proportionate” as synonyms, there can be a subtle distinction between them.
From Webster’s New World College Dictionary:
proportionate and proportional: both imply a being in due proportion, the former usually being preferred with reference to two things that have a reciprocal relationship to each other [the output was proportionate to the energy expended], and the latter, with reference to a number of similar or related things [proportional representation].
Garner’s Modern American Usage says that “proportional” means “of or relating to proportion” or “in due proportion,” while “proportionate” means “proportioned; adjusted in proportion.” But Garner’s also acknowledges that “at times the distinction is foiled by the frequent interchangeability of the terms.”
By those lights, the “proportional match” above is probably correct, in that it is a “due proportion” of a whole. And so could be the “proportionate” number of teaching and administrative positions, especially if some teaching and administrative positions were eliminated.
Regardless, in most cases, “proportional” and “proportionate” are synonomous, and journalists will be okay using either one. Call it fielder’s choice.
But the “proportionable mix”? That one is archaic, and “has no place today,” Garner’s says.
“Proportionalize,” which shows up occasionally, is just an unnecessary verb variant of “proportion” and not listed in any mainstream dictionary.
A quick Nexis search confirms Garner’s contention that “proportional is more than twice as common in print as proportionate.” (Most current uses of “proportionable” occur in contemporary accounts from the fourteenth, fifteenth, and sixteenth centuries.)
The tables are turned, however, when one adds the prefix “dis.” In one week, “disproportional/ly” had only four uses, while “disproportionate/ly” had more than 300. (“Disproportionably,” thankfully, shows up only a handful of times, most recently in December.)
Why, all other parts of speech being equal, should people want to use the “al” sound when it’s a positive usage, and “ate” when it’s negative?
Your guess is as good as anyone’s. We’d love to hear your theories.