I have a question on assumption changes for DB plans. When the expected return on plan asset increases, I understand it does not impact the FV of plan asset because it only looks at actual returns but how come it does not impact PBO? PBO includes actuarial gains and losses and this component includes Actual return on plan asset - Expected plan assets * Expected return. Unless the adjustment for actual and expected return only impacts periodic pension costs? Is the definition of actuarial gains and losses different for PBO and periodic expense calculation purposes? Do actuarial gains and losses for PBO calculation only include changes in assumption?