As the third-quarter corporate earnings season gets underway this week, markets are about to get a sense of the degree to which rising business input costs were absorbed by firms and pulled down their bottom lines. Nineteen S&P 500 firms report earnings this week starting with the big banks. According to Refinitiv IBES forecasts, profit growth is estimated to come in at 30 percent in the third quarter, down from 96 percent in the previous three-month period. Increases in commodity costs, labor shortages and supply bottlenecks, and consumer price inflation will be a big part of the story as the corporate earnings season gets underway. Queen’s College President Mohamed El-Erian wrote in an Oct. 10 Twitter post that, “with (non-transitory) cost #inflation currently exceeding price inflation, either profit margins will be eroded, or prices will rise faster, or some combination of both.” Earnings results will provide a sense of the degree …