You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Economic_inequality

Context:
Research by Harvard economist Robert Barro, found that there is "little overall relation between income inequality and rates of growth and investment". According to work by Barro in 1999 and 2000, high levels of inequality reduce growth in relatively poor countries but encourage growth in richer countries. A study of Swedish counties between 1960 and 2000 found a positive impact of inequality on growth with lead times of five years or less, but no correlation after ten years. Studies of larger data sets have found no correlations for any fixed lead time, and a negative impact on the duration of growth.

Question:
What does high levels of inequality do for economic growth in richer countries?

encourage