Investing.com -You've probably noticed that Corporate America has been returning billions of dollars to shareholders through stock buybacks and dividend increases. Well, it may be of historic proportions.S&P Dow Jones Indices estimates that companies in the S&P 500 are on track to spend $1 trillion on buybacks and dividend hikes this year.Buybacks are up 72%, driven by a large number of unusually large ones, including Apple (NASDAQ:AAPL), PepsiCo (NASDAQ:PEP), Wells Fargo (NYSE:WFC) and Cisco. Meanwhile, one out of three S&P 500 companies has raised its stock dividend so far this year.Much of the money spent has come from savings resulting from the late 2017 corporate tax cut, which took rates from 35% to 21%.Critics say corporations should be spending more money on new investment and worker compensation.Goldman Sachs (NYSE:GS) recently issued a report saying research shows companies with a buyback-and-dividend strategy have underperformed the S&P 500 in the past two years.