Across the U.S. economy, a number of industries are facing the same formidable challenge: Replenishing a workforce that is being diminished by a surge of retirements that began during the pandemic and has continued since. Since 2019, the proportion of retirees in the U.S. population has risen from 18% to nearly 20% — equivalent to about 3.5 million fewer workers. And the trend seems sure to accelerate: The percentage of workers who are 55 or older is nearly 24%, up from only about 15% two decades ago. Among the industries that have encountered frustrating labor shortages, magnified by a steady exodus of older workers, are airline maintenance, construction, manufacturing and nursing, along with some professional industries such as accounting.