Item 7A. Quantitative and Qualitative Disclosures About Market Risk

We are exposed to various market risks, including the potential loss arising from adverse changes in interest rates. We use derivative and other financial instruments in the normal course of business to mitigate interest rate. We do not use derivative financial instruments for speculative or trading purposes. Derivatives are recorded on the consolidated balance sheets at fair value (see Note 21 to the Consolidated Financial Statements).

To illustrate the effect of movements in the interest rate markets, we performed a market sensitivity analysis on our hedging instruments. We applied various basis point spreads to the underlying interest rate curves of the derivative portfolio in order to determine the change in fair value. Assuming a one percentage point change in the underlying interest rate curve, the estimated change in fair value of each of the underlying derivative instruments would not be material.

Interest Rate Risk

At December 31, 2019, our exposure to interest rate risk is primarily on our variable rate debt. At December 31, 2019, $42 million of our variable-rate debt was hedged by interest rate swap transactions. The interest rate swaps are designated as cash flow hedges, with the objective of managing the exposure to interest rate risk by converting the interest rates on our variable-rate debt to fixed interest rates.

Interest rate fluctuations will generally not affect our future earnings or cash flows on our fixed rate debt and assets until their maturity or earlier prepayment and refinancing. If interest rates have risen at the time we seek to refinance our fixed rate debt, whether at maturity or otherwise, our future earnings and cash flows could be adversely affected by additional borrowing costs. Conversely, lower interest rates at the time of refinancing may reduce our overall borrowing costs. However, interest rate changes will affect the fair value of our fixed rate instruments. At December 31, 2019, a one percentage point increase or decrease in interest rates would change the fair value of our fixed rate debt by approximately $365 million and $401 million, respectively, and would not materially impact earnings or cash flows. Additionally, a one percentage point increase or decrease in interest rates would change the fair value of our fixed rate debt investments by approximately $2 million and less than $7 million, respectively, and would not materially impact earnings or cash flows. Conversely, changes in interest rates on variable rate debt and investments would change our future earnings and cash flows, but not materially impact the fair value of those instruments. Assuming a one percentage point change in the interest rate related to our variable-rate debt and variable-rate investments, and assuming no other changes in the outstanding balance at December 31, 2019, our annual interest expense and interest income would increase by approximately $3 million and $1 million, respectively.

Market Risk

We have investments in marketable debt securities classified as held-to-maturity because we have the positive intent and ability to hold the securities to maturity. Held-to-maturity securities are recorded at amortized cost and adjusted for the amortization of premiums and discounts through maturity. We consider a variety of factors in evaluating an other-than-temporary decline in value, such as: the length of time and the extent to which the market value has been less than our current adjusted carrying value; the issuer’s financial condition, capital strength and near-term prospects; any recent events specific to that issuer and economic conditions of its industry; and our investment horizon in relationship to an anticipated near-term recovery in the market value, if any. At December 31, 2019, both the fair value and carrying value of marketable debt securities was $20 million.