Could anyone please explain the relationship between willingness to pay and net present value, and how these then translate to cost benefit analysis?
Thanks.

Dear friend
Willingness to pay is simply among the tools you learn about people attitude/perception of offer for the thing under consideration. In simple economic term it equals to 'expressed demand' (unlike to actual demand). Or the means to understand how much value he/she assign to the thing. Generally it is a hypothetical expression express demand for the goods under consideration

On the other hand Present value and CBE are work out based on actual values like price, cost etc. Based on your research and data you can bring values of willingness to pay for benfiet estimation in CBE but I am not sure the appllication for present value.

Correct?