immediately following the financial crisis of 2009, the federal reserve's balance sheet grew by north of $2 acng 5 trillion in your comment following up to congresswoman ann wagner's question, you noted that the federal reserve has been mostly holding to maturity. i'm wondering if you could comment what the economic indicator that you are looking at at the federal reserve between 2009 into 2019 as the federal reserve dropped the balance sheet by roughly half of a trillion dollars, and whether or not those same economic indicators will be guiding you as you make determinations in the fed as to whether or not you'll be needing to hold those reserves all the way through their maturity or if there will be opportunities to reduce the fed's balance sheet in advance of that maturity >> we waited until the economy was well down the path of recovery before we even started to think about shrinking the size of the balance sheet. the other thing that we did was we froze the balance sheet at the end of 2014. we froze the size of the balance sheet -- pardon me -- for a period of three years, so the economy wa