This PR completes the process of refactoring the net interest model as described in #43. This switches the advancing of the debt during the budget window to use a forecast for delta instead of just advancing by assets and then including the response. This has no effect on the tests or the baseline; its only relevance will be once BRC switches to using the TCJA's behavioral effects (specifically, on optimal debt) as the baseline.
I also fixed a small error in the pass-through response, which was not yet being tested.
This PR completes the process of refactoring the net interest model as described in #43. This switches the advancing of the debt during the budget window to use a forecast for delta instead of just advancing by assets and then including the response. This has no effect on the tests or the baseline; its only relevance will be once BRC switches to using the TCJA's behavioral effects (specifically, on optimal debt) as the baseline.
I also fixed a small error in the pass-through response, which was not yet being tested.