I am looking to clarify my understanding of the following terms : duration, spread duration, partial duration.

If I am evaluating a coporate bond with both Treasury risk and credit spread risk, then duration is just the % change of the price of the bond with respect to 100bp in the Yield to Maturity. In this case, duration measures how a change in yield impacts the overall price. It doesn’t matter if the yield change was a result of Treasury or credit spread.

For spread duration, it is the % change in the price of the bond with respect to 100bp change in the spread. This basically reflects the risk of the credit spread component assuming Treasuries are held constant.

Is this all correct? Is there a measure of duration that measures specifically Treasury risk. Can’t we subtract spread duration from overall duration.

Secondly, is partial duration then the sensitivity of the price of the bond with respect to changes in specific parts of the yield curve? Is this the Treasury curve? If I have a bond with 30 year maturity and the partial duration at the 5 year point is X, does this mean the bond’s sensivitiy if shocks are applied at the 5 year point on the Treasury curve?