Definition: In this task, you are given a statement spoken by a politician in natural language. Your task is to generate the subject of the discussion for the given statement. The subject generated is not necessarily a part of the given input. Your answer should contain one or more words.
Input: From 1947 to 1979, family incomes for rich, middle-income and poor Americans grew about the same rate. But since 1979, incomes for rich families have grown much faster.

families