I would be uncomfortable raising the federal funds rate if readings on wage growth, core consumer prices, and other indicators of underlying inflation pressures were to weaken, if market-based measures of inflation compensation were to fall appreciably further, or if survey-based measures were to begin to decline noticeably.

By putting downward pressure on interest rates, the Fed is trying to make financial conditions more accommodative - supporting asset values and lower borrowing costs for households and businesses and thus encouraging the spending that spurs job creation and a stronger recovery.

Maturity transformation is a central part of the economic function of banks and many other types of financial intermediaries.

Janet Yellen Quotes