Difference between yield curve and spot rate curve and their determinants

Dear all

In relation to the term structure theories, I would like to know the difference between yield curves and spot rave curves. When we are talking about pure expectations, liquidity preference etc, are we talking about the shape of yield curves or spot rate curves?

Generally, when people talk about “the yield curve”, they mean the (Treasury) par curve. So, in the discussions about pure expectations, and liquidity preference and preferred habitat and so on, think “par curve”.

However, because there is a one-to-one correspondence between the par curve and the spot curve (i.e., given any par curve, there is only one equivalent spot curve, and given any spot curve there is only one equivalent par curve), anything that is said about the par curve is also true for the spot curve.