Deng Xiaopeng implemented economic reforms in China known as the Four Modernizations to modernize agriculture, industry, national defense, and science and technology. He reversed Mao's policies by eliminating communes and extending market reforms to industry. These economic policy changes resulted in significantly increased household incomes and profits from foreign trade and investment between 1978 and 1999. However, democratic student protests in Tiananmen Square in 1989 were violently suppressed after Deng upheld the Communist Party's authority. Jiang Zemin later succeeded Deng as president and upheld his foreign policies while attempting to improve relations with the United States.