Investing.com - Cisco. Boeing (NYSE:BA). Amgen (NASDAQ:AMGN). MasterCard. Procter & Gamble.Major companies from virtually every sector have announced multi-billion dollar share buyback programs this year. Buybacks are running at a record rate, as companies return cash to shareholders.Goldman Sachs (NYSE:GS) estimates corporate buybacks will increase 23% to $650 billion in 2018.The big driver is lower corporate taxes.Not only are companies paying a lower rate on profits earned in the U.S., they are taking advantage of a one-time opportunity to repatriate profits from overseas at a discounted rate.Bank of America (NYSE:BAC) estimates companies will budget almost 40% of the $1.2 trillion held overseas on share buybacks this year. When companies last had a chance to repatriate profits in 2004, they spent about 80% of the money on buybacks.Companies use buybacks as a vote of confidence in the company. They also improve earnings by reducing the number of outstanding shares.