due to certain impairment indicators at the About Group, we performed an interim impairment test as of June 24,  2012.  Our expectations for future operating results and cash flows at the About Group in the long-term were lower  than our previous estimates, primarily driven by a reassessment of the sustainability of our estimated long-term  growth rate for display advertising. The reduction in our estimated long-term growth rate resulted in the carrying  value of the net assets being greater than their fair value, and therefore a write-down of goodwill to its fair value was  required. The fair value of the About Group’s goodwill was the residual fair value after allocating the total fair value  of the About Group to its other assets, net of liabilities.  The total fair value of the About Group was determined using a discounted cash flow model (present value of  future cash flows). We estimated a 3.5% annual growth rate to arrive at a residual year representing the perpetual  cash flows of the About Group. The residual year cash flow was capitalized to arrive at the terminal value of the  About Group. Utilizing a discount rate of 15.0%, the present value of the cash flows during the projection period and  terminal value were aggregated to estimate the fair value of the About Group. In our 2011 annual impairment test, we  had assumed a 5.0% annual growth rate and a 13.8% discount rate. In determining the appropriate discount rate, we  considered the weighted-average cost of capital for comparable companies.  The impairment charge totaling $5.5 million in the preceding table for the cost method investments in 2012,  which was primarily related to our investment in Ongo Inc., was due to events surrounding ceasing the operations of  our investments (see Note 5). We determined the fair value of these investments using the market and income  approaches. The market approach includes the use of financial metrics and ratios of comparable companies. The  income approach includes the use of a discounted cash flow model.  Our marketable securities, which include U.S. Treasury securities, corporate debt securities, U.S. government  agency securities, municipal securities, certificates of deposit and commercial paper, are recorded at amortized cost  (see Note 3). As of December 28, 2014 and December 29, 2013, the amortized cost approximated fair value because of  the short-term maturity and highly liquid nature of these investments. We classified these investments as Level 2  since the fair value estimates are based on market observable inputs for investments with similar terms and  maturities. The carrying value of our long-term debt was approximately $420 million as of December 28, 2014 and $677  million as of December 29, 2013. The fair value of our long-term debt was approximately $527 million as of  December 28, 2014 and $819 million as of December 29, 2013. We estimate the fair value of our debt utilizing market  quotations for debt that have quoted prices in active markets. Since our debt does not trade on a daily basis in an  active market, the fair value estimates are based on market observable inputs based on borrowing rates currently  available for debt with similar terms and average maturities (Level 2). We sponsor several single-employer defined benefit pension plans, the majority of which have been frozen. We  also participate in joint Company and Guild-sponsored plans covering employees of The New York Times Newspaper  Guild, including The Newspaper Guild of New York - The New York Times Pension Fund, which was frozen and  replaced with a new defined benefit pension plan, The Guild-Times Adjustable Pension Plan.  We also have a foreign-based pension plan for certain employees (the “foreign plan”). The information for the  foreign plan is combined with the information for U.S. non-qualified plans. The benefit obligation of the foreign plan  is immaterial to our total benefit obligation. Financial Instruments Disclosed, But Not Reported, at Fair Value 9. Pension Benefits Single-Employer Plans P. 78 – THE NEW YORK TIMES COMPANY