The text is poorly worded on this questoin IMO. They should have not used the word widen, and should have simply said “for the following bonds, the yields must either increase, or decrease, by x amount”
They use the word widen despite it not really being a spread to any benchmark. Semantics aside, when I think of widening spreads, I think of falling prices and increasing interest rates. That is why I have an issue with this problem. The wording makes it seem like you have to pick one of the 3 bonds and show how much yields in that country must increase (“widen” for their purposes) to offset the yield advantage earned. Since U.K is the only bond at an advantage to the U.S., we know that since we are working with “widening”, we must find out how much the U.K interest rates must INCREASE…. therefore we use the U.K.’s duration, and not the largest… at least that is what would make sense to me because if you try to apply the dollars duration using the breakeven number you get, it doesn’t work.
Now the text uses JPY’s duration because it is the largest – and thats the problem. They said how much must spreads on these particular bonds “WIDEN”, yet then they reference the JPY bond specifically…. but the JPY is at a yield disadvantage, so yields in JPY must decrease, or NARROW in order to catch up to the USD, not WIDEN.
This is hard to word properly, I am doing my best…. I do believe this is either an error or a very poorly worded question