MADRID - The world is facing a serious recession but should avoid a repeat of the Great Depression it experienced in the 1930s, a top U.S. economist said Sunday in an interview published in Spain.

This recession would be more serious than others, Jeffrey Sachs, a special advisor to the United Nations secretary general, told the daily El Pais. Allowing Lehman Brothers to collapse was a "huge mistake" that had worsened the crisis, he argued.