From a General Accounting Office report, "Social Security: Implications for Private Pension Plans," released in October.
"A reduction in Social Security benefits will raise compensation costs for employers with plans that directly offset the earned pension benefit with a portion of the worker's Social Security benefit. In response, employers might redesign the plan feature, absorb the increased cost, or shift the cost to customers through price increases or to employees through employment or compensation reductions, among other possible changes.
"In reaction to increasing the normal retirement age for Social Security, employers could face added pension costs for subsidizing early retirement and may redesign their plans to raise the eligibility age for retirement benefits. Workers may also respond to Social Security reforms that increase their contributions or reduce expected benefits by adjusting their savings behavior - for example, by increasing participation in 401(k) plans or accumulating more savings through other vehicles. They might also choose to work more, retire later, or demand higher pension compensation. ..."