Stocks are booming while companies shed millions of workers from payrolls. WSJ explains why the stock market seems disconnected from economic reality in the U.S.  The global economic collapse caused by the coronavirus won’t be as severe as estimated earlier, the International Monetary Fund predicted Tuesday, thanks to strong government intervention world-wide and a swift recovery in China. The world’s gross domestic product is forecast to decline by 4.4% this year, not as sharp as the 5.2% drop the IMF projected in June but still the most severe downturn since the Great Depression. World output will grow 5.2% in 2021, down from an earlier estimate of 5.4%. China,…