The math is pretty simple: A lack of purchasing power for consumers has led to a lack of pricing power for companies. When it comes to the U.S. economy big-picture outlook, the ramifications are more complicated, and not particularly pleasant. Wednesday's producer price index reading, showing a monthly decline of 0.5 percent, demonstrates a larger problem: At a time when policymakers are hoping to generate the kind of inflation that would indicate strong growth, the reality is that deflation is looming as the larger threat. Declining prices often would be treated as a net positive by consumers, but income weakness...