A recent study in JAMAPaediatrics, a science journal, calculated that the lifetime cost of supporting an American with autism was $1.4m-2.4m. Paul Leigh of the University of California at Davis and Juan Du of Old Dominion University have added up not only the cost of care but also the opportunity costs of autism in America. They include an estimate of the output lost when autistic people are jobless or underemployed, and when their relatives cut back on working hours to look after them. They put the total at $162 billion-367 billion in 2015, the equivalent of 0.9-2% of GDP, on a par with both diabetes and strokes. By 2025 the figure could exceed $1 trillion, they predict. Confronting autism is costly, but failing to do so may cost even more.