BP Annual Report and Form 20-F 2011 - Company Reporting

Notes on financial statements37. Pensions and other post-retirement benefits continuedThe assumed rate of investment return, discount rate, inflation, US healthcare cost trend rate and the mortality assumptions all have a significant effect onthe amounts reported.A one-percentage point change in the following assumptions for the group’s plans would have had the effects shown in the table below. Theeffects shown for the expense in 2012 include current service cost and interest on plan liabilities.$ millionOne percentage pointIncrease DecreaseInvestment returnEffect on pension and other post-retirement benefit expense in 2012 (351) 351Discount rateEffect on pension and other post-retirement benefit expense in 2012 (78) 101Effect on pension and other post-retirement benefit obligation at 31 December 2011 (5,585) 7,285Inflation rateEffect on pension and other post-retirement benefit expense in 2012 494 (381)Effect on pension and other post-retirement benefit obligation at 31 December 2011 5,323 (4,301)US healthcare cost trend rateEffect on US other post-retirement benefit expense in 2012 27 (22)Effect on US other post-retirement obligation at 31 December 2011 350 (290)One additional year of longevity in the mortality assumptions would have the effects shown in the table below. The effect shown for the expense in 2012includes current service cost and interest on plan liabilities.UKpensionplansUSpensionplansUS other postretirementbenefitplansOne additional year’s longevityEffect on pension and other post-retirement benefit expense in 2012 44 5 4 9Effect on pension and other post-retirement benefit obligation at 31 December 2011 609 111 73 166$ millionGermanpensionplansFinancial statementsBP Annual Report and Form 20-F 2011 237