"...[b]etween rich and poor" and "...[b]etween the rich and the poor"

My colleague and I were discussing a student's paper.

We agreed that according to our experiences and knowledge of English, the following sentence is grammatically correct: "The difference between the rich and the poor in our city stems from..."

But, another colleague claimed that it would be acceptable to say, "The difference between rich and poor in our city stems from..."

While searching for examples of each, we found ourselves befuddled.

Why are both versions seemingly acceptable?

Solution 1:

It's another example of common elision in standard speech and writing:

The rich people and the poor people suffer similarly.

The rich and the poor suffer similarly.

Rich and poor suffer similarly.

All say the same thing, and are easily understood. Leaving out the articles and nouns adds rhythm and vigor to writing. Consider this (extreme) example:

Including every (one of the) (possible) (words that is an) article and (every possible word that is a) noun makes (for writing that is) tedious (when one is) reading (it).

This is one of those things that us technical writers struggle with. Or, should I say, "with which we struggle." Daily.