The Federal Reserve lowered the discount rate from 2007 to 2009 as a response to a slowing economy during the Great Recession, aiming to stimulate economic activity and combat high unemployment.
Using the data from the table provided and historical context from the Federal Reserve's actions, we can determine that the condition under which the Federal Reserve would change the discount rate, as it did from 2007 to 2009, was in response to a slowing economy. In Episode 9, during the Great Recession in 2008, the Federal Reserve cut interest rates aggressively, down to nearly 0% by 2009. This action was taken when traditional monetary policy tools, such as open market operations, were insufficient due to already low-interest rates, which could not be reduced into negative territory.
Therefore, it was necessary for the Federal Reserve to lower the discount rate as a form of economic stimulus to encourage lending and investment, when the economy was in recession and needed support. The lowering of the discount rate is a part of a broader monetary policy strategy to inject liquidity into the financial system, spur economic activity, and combat the high unemployment rates that typically accompany a recession.