Career employees of US state and local governments such as teachers, civil servants, police, firefighters, and sanitation workers are usually covered by defined benefit (DB) public pension plans. The financial positions of such pensions are typically reported in documents called Comprehensive Annual Financial Reports (CAFRs). Public pension plan CAFRs usually include extensive data about plan assets, cash flows, expenses, investment policy, and performance. This information is helpful to watchdogs and other parties interested in monitoring the financial integrity of pools of assets that can run into hundreds of billions of dollars. Information about public plan liabilities, however, is far more difficult to obtain. A typical CAFR will disclose the actuarial methods and assumptions used in the liability calculations, including plan provisions, data on participant ages, projections on salaries and service, and actuarial methods. The measure of the actuarial liabilities is highly dependent upon the methods and assumptions chosen by the plan actuary, or contained in local statutes and regulations. Actuarial assumptions are typically consistent with Actuarial Standards of Practice (ASOPs), especially ASOP No. 4 and ASOP No. 27 (for economic assumptions), and ASOP No. 35 (for demographic assumptions). The economic assumptions (expected returns on invested assets, future inflation, and salary increases) are designed to facilitate a long-range budgeting process and are not intended to reflect current market conditions. The actuarial liabilities developed in accordance with these long range projections are not well-linked to economic values and leave several important pension financial questions unanswered. This chapter focuses on three such questions of particular importance to public pension plan valuation: