The U.S. economy is rounding out 2014 in a sweet spot of robust growth, sustained hiring and falling unemployment, stirring optimism that a postrecession breakout has arrived.

A fuller picture of the year-end trends emerged Tuesday when the Commerce Department, in separate reports, said the U.S. economy expanded at a 5% seasonally adjusted annual rate in the third quarter, its strongest pace in 11 years, and reported that consumer spending accelerated last month amid rising incomes and falling gasoline prices.

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