Hyperinflation has a profoundly negative effect on poor people. The writer failed to cite the author's idea. The enormously noxious effects of hyperinflation are especially hard on the poor. The writer cited the author's idea, but failed to use quotations around the key words. When dealing with quotations, the issue isn't necessarily the number of words, but rather their importance.
Some source material is considered to be public domain, and as such, requires no citation.
Public Domain information is that information gained from experience or observation without the aid of external resources. The Perkins building is a tall, brick structure in downtown Tacoma. If a writer has never seen the Perkins building, then the above passage, if used in a paper, would require citation. When this type of information is used, it generally does not need to be cited. The game is not over until the fat lady sings.