(Last Word) The combined cost of Social Security and Medicare programs was what percent of U.S. GDP in 2011?

The gravity model offers a logical explanation for the fact that

A) trade between Asia and the U.S. has grown faster than NAFTA trade. B) trade in services has grown faster than trade in goods. C) trade in manufactures has grown faster than in agricultural products. D) Intra-European Union trade exceeds international trade by the European Union. E) the U.S. trades more with Western Europe than it does with Canada.

The idea that investors today compare the returns on bonds with differing times to maturity to see which is expected to give them the highest return is the underlying principle behind the ________ of the term structure of interest rates

A) expectations theory B) investors' viewpoint analysis C) segmented-markets theory D) yield comparison theory