Outgoing Treasury Secretary Janet Yellen conceded that COVID-19 stimulus packages could have contributed somewhat to persistent U.S. inflation. The COVID-19 fiscal stimulus packages may have contributed “little bit to the inflation” but said that the main driving force was supply chain issues, she told CNBC on Wednesday morning. In the United States, there were “simply huge supply chain problems” due to COVID-19, Yellen said. She said critical good shortages “started pushing up prices a great deal.” The $1.9 trillion COVID-19 relief bill, known as the 2021 American Rescue Plan, and other government spending measures were needed, she said. Yellen also did not answer whether she has any regrets about the extra fiscal stimulus and government spending….