Table of Contents Tax Deleverage & Dividends Critical Accounting Estimates Pension and Other Postretirement Benefits Discount Rates 60 As of December 31, 2020, on a weighted-average basis, the discount rates used were 1.84% for our defined benefit pension plans and 2.10% for our OPEB plans. The change from the weighted-average discount rates of 2.55% for our defined benefit pension plans and 2.91% for our postretirement plans as of December 31, 2019 is primarily the result of declining interest rates during 2020. The assumed discount rates are used to present-value future benefit obligations based on each plan's respective estimated duration. Our pension and postretirement discount rates are based on our annual evaluation of high quality corporate bonds in various markets based on appropriate indices and actuarial guidance. We believe that our discount rate assumptions are appropriate; however, significant changes in our assumptions may materially affect our pension and OPEB obligations and related expense. Accounting for pension and OPEB plans requires that we make assumptions that involve considerable judgment which are significant inputs in the actuarial models that measure our net pension and OPEB obligations and ultimately impact our earnings. These include the discount rate, long- term expected rate of return on assets, compensation trends, inflation considerations, health care cost trends and other assumptions, as well as determining the fair value of assets in our funded plans. Specifically, the discount rates, as well as the expected rates of return on assets and plan asset fair value determination, are important assumptions used in determining the plans' funded status and annual net periodic pension and OPEB costs. We evaluate these critical assumptions at least annually on a plan and country-specific basis. We also, with the help of actuaries, periodically evaluate other assumptions involving demographic factors, such as retirement age, mortality and turnover, and update them to reflect our experience and expectations for the future. While we believe that our assumptions are appropriate, significant differences in our actual experience or significant changes in our assumptions may materially affect our net pension and postretirement benefit obligations and related expense. Our defined benefit pension plans cover certain current and former employees in the U.S., Canada, the U.K. and Japan. Benefit accruals for the majority of employees in our U.S. and U.K. plans have been frozen and the plans are closed to new entrants. In the U.S., we also participate in, and make contributions to, multi-employer pension plans. Our OPEB plans provide medical benefits for retirees and their eligible dependents as well as life insurance and, in some cases, dental and vision coverage, for certain retirees in Canada, the U.S., and Europe. The U.S., Canada and U.K. defined benefit pension plans are primarily funded, but the Japan plan and all OPEB plans are unfunded. We also offer defined contribution plans in each of our segments. Our consolidated financial statements are prepared in accordance with U.S. GAAP. In connection with the preparation of our consolidated financial statements, we are required to make judgments and estimates that significantly affect the reported amounts of assets, liabilities, revenues and expenses and related disclosures. Our estimates are based on historical experience, current trends and various other assumptions we believe to be relevant under the circumstances. We review the underlying factors used in our estimates regularly, including reviewing the significant accounting policies impacting the estimates, to ensure compliance with U.S. GAAP. However, due to the uncertainty inherent in our estimates, actual results may be materially different. We have identified the accounting estimates below as critical to understanding and evaluating the financial results reported in our consolidated financial statements. For a complete description of our significant accounting policies, see Part II—Item 8 Financial Statements and Supplementary Data,  Note 1, "Basis of Presentation and Summary of Significant Accounting Policies." We currently intend to maintain our investment grade debt rating and we are committed to further deleveraging in 2021 in accordance with our plans. Further, our current expectation is that the Company's board of directors will be in a position to reinstate a dividend in the second half of 2021. We expect our effective tax rate to be in the range of 20 to 23 percent for 2021, which remains subject to additional guidance, final regulations, and tax law changes issued from the U.S. government.