THEKEY TO UNDERSTANDING the financial implications of corporate pension plans -before and after the passage of ERISA-is the economic value of claims on a pension plan. Beneficiaries have regarded their claims as a bona fide retirement fund. On the other hand, sponsoring companies, their actuaries, their accountants, their creditors, and their stockholders have regarded pension claims lightly. Thus corporate pension plans have traditionally had a "something for nothing" aspect about them, whereby their value to beneficiaries seemed to exceed the financial burden they imposed on the sponsoring company. What are pension claims really worth?