Teacher:Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
Teacher: Now, understand the problem? Solve this instance: Passage: Studies on income inequality and growth have sometimes found evidence confirming the Kuznets curve hypothesis, which states that with economic development, inequality first increases, then decreases. Economist Thomas Piketty challenges this notion, claiming that from 1914 to 1945 wars and 'violent economic and political shocks' reduced inequality. Moreover, Piketty argues that the 'magical' Kuznets curve hypothesis, with its emphasis on the balancing of economic growth in the long run, cannot account for the significant increase in economic inequality throughout the developed world since the 1970s. Question: What have studies on income inequality sometimes found evidence confirming?
Student:
Kuznets curve hypothesis