Some 40% of the nation’s baby formula is out of stock, causing new mothers to hunt from store to store to feed their infants. Abbott Laboratories recalled several brands and shut down a plant in Michigan after complaints that four infants fell severely ill with a dangerous bacteria after ingesting its powdered formula. The real culprit is the government policies that have limited formula options that are concentrated in the U.S. There are only four major manufacturers of formula in the country. The FDA said Friday the Centers for Disease Control and Prevention closed its investigation after finding no more cases of infant illness. It’s not clear when the FDA was made aware of the problems at the plant and why it didn’t take action sooner than it took action sooner. . . .