Further Federal Reserve asset purchases will not speed up the labour market recovery and could damage the

Question:

Further Federal Reserve asset purchases will not speed up the labour market recovery and could damage the Fed’s credibility, said Federal Reserve Bank of Philadelphia President Charles Plosser, who is opposed to further asset buying of any size at this time.
a. Describe the asset purchases that are causing Charles Plosser concern.
b. How might asset purchases damage the Fed’s credibility?