An article in the Wall Street Journal notes that before the financial crisis of 2007-2009, the Fed "managed just one short-term interest rate and expected that to be enough to meet its goals for inflation and unemployment."
a. What short-term interest rate is the article referring to? How would the Fed expect controlling that one interest rate would allow it to meet its goals for inflation and unemployment?
b. The article also notes that after the financial crisis, "the Fed is working through a broader spectrum of interest rates." What does "a broader spectrum of interest rates" mean? How is the Fed able to affect a broader spectrum of interest rates?