Not one projection of doom in this editorial would surprise President-elect Biden. He knows. Yet as a candidate, he vacillated between pandering to voters and acknowledging that something has to change. He proposes higher Social Security benefits for low earners. And he would extend the payroll tax — now 6.2% for workers and the same for their employers. For 2021, that taxation applies until a worker has earned $142,800. But Biden’s plan also would apply the tax to wages above $400,000. So if you earn, say, $500,000 a year, you’d pay the Social Security tax on your first $142,800 and on your last $100,000, but not on the $257,200 between those thresholds.