主题：美国债券股票收益率估计(开始于1928年）

Rate Estimation Historical Returns on Stocks, Bonds and Bills - United States

	Arithmetic Average		Geometric Average
	Stocks - T. Bills	Stocks - T. Bonds	Stocks - T. Bills	Stocks - T. Bonds
1928-2010	7.62%	6.03%	5.67%	4.31%
Standard Error	2.25%	2.38%
1961-2010	5.83%	4.13%	4.44%	3.09%
Standard Error	2.42%	2.69%
2001-2010	1.37%	-2.26%	-0.79%	-4.11%
Standard Error	6.73%	9.00%

从长远看美国的ERP风险为5.67%。