The worst U.S. inflation outbreak in a generation turns five years old this month, a defining economic shock that is still driving policy debates, influencing national politics, and frustrating Federal Reserve officials trying to restore the pace of price increases to their 2% target after a monumental miss. When nose-diving inflation at the start of the COVID-19 pandemic touched off concerns of a dangerous downward spiral in wages and prices, it was actually considered a good sign when prices across a variety of gauges began rising by more than 2% annually in March 2021. Fed officials even planned to encourage the emerging trend with continued low interest rates.