Hayek's ideas on spontaneous order and the importance of prices in dealing with the knowledge problem has inspired a debate on economic development and transition economies after the fall of the Berlin wall. For instance, economist Peter Boettke elaborated in detail on why reforming socialism failed and the Soviet Union broke down. Economist Ronald McKinnon uses Hayekian ideas to describe the challenges of transition from a centralized state and planned economy to a market economy. Former World Bank Chief Economist William Easterly emphasizes why foreign aid tends to have no effect at best in books such as "The White Man's Burden: Why the West's Efforts to Aid the Rest Have Done So Much Ill and So Little Good".