The U.S. economy grew at a revised 4.6 percent annualized rate in the second quarter of 2014, the Commerce Department announced Friday. That is up from the previous estimate of 4.2 percent. The increase follows a 2.1 percent decline in the first quarter of the year, which economists are now viewing as an aberration. The spring growth rate is the highest since the final quarter of 2011. The increase was largely triggered by increased corporate spending on equipment and properties, as well as investments in nonresidential properties.