| ($ in millions) |
Pension benefits | Postretirement benefits |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |
2013 | 2012 | 2013 | 2012 | |||||||||
|
Benefit obligation, beginning of year |
$ | 6,727 | $ | 5,831 | $ | 803 | $ | 716 | |||||
|
Service cost |
140 | 152 | 12 | 13 | |||||||||
|
Interest cost |
265 | 298 | 28 | 36 | |||||||||
|
Participant contributions |
1 | 1 | 18 | 20 | |||||||||
|
Actuarial (gain) loss |
(406 | ) | 756 | (32 | ) | 76 | |||||||
|
Benefits paid (1) |
(892 | ) | (312 | ) | (57 | ) | (59 | ) | |||||
|
Plan amendments |
(506 | ) | — | — | — | ||||||||
|
Translation adjustment and other |
(31 | ) | 1 | (5 | ) | 1 | |||||||
|
Curtailment gain |
(1 | ) | — | (285 | ) | — | |||||||
| | | | | | | | | | | | | | |
|
Benefit obligation, end of year |
$ | 5,297 | $ | 6,727 | $ | 482 | $ | 803 | |||||
| | | | | | | | | | | | | | |
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