Table:
|  |  |  | Year Ended December 31, |
| --- | --- | --- | --- |
| (In thousands, unaudited) | 2019 | 2018 | 2017 |
| Net income (loss) | $ (19,931) | $ (50,571) | $ 65,299 |
| Add (subtract): |  |  |  |
| Interest expense, net of interest income | 136,660 | 134,578 | 129,786 |
| Income tax benefit | (3,714) | (24,127) | (124,927) |
| Depreciation and amortization | 381,237 | 432,668 | 291,873 |
| EBITDA | 494,252 | 492,548 | 362,031 |
| Adjustments to EBITDA: |  |  |  |
| Other, net (1) | (8,847) | 549 | 19,314 |
| Investment distributions (2) | 35,809 | 39,078 | 29,993 |
| Gain on extinguishment of debt | (4,510) | — | — |
| Non-cash, stock-based compensation | 6,836 | 5,119 | 2,766 |
| Adjusted EBITDA | $ 523,540 | $ 537,294 | $ 414,104 |
Paragraphs:
Non-GAAP Measures
In addition to the results reported in accordance with US GAAP, we also use certain non-GAAP measures such as EBITDA and adjusted EBITDA to evaluate operating performance and to facilitate the comparison of our historical results and trends. These financial measures are not a measure of financial performance under US GAAP and should not be considered in isolation or as a substitute for net income as a measure of performance and net cash provided by operating activities as a measure of liquidity.
They are not, on their own, necessarily indicative of cash available to fund cash needs as determined in accordance with GAAP. The calculation of these non-GAAP measures may not be comparable to similarly titled measures used by other companies. Reconciliations of these non-GAAP measures to the most directly comparable financial measures presented in accordance with GAAP are provided below.
EBITDA is defined as net earnings before interest expense, income taxes, and depreciation and amortization. Adjusted EBITDA is comprised of EBITDA, adjusted for certain items as permitted or required under our credit facility as described in the reconciliations below. These measures are a common measure of operating performance in the telecommunications industry and are useful, with other data, as a means to evaluate our ability to fund our estimated uses of cash.
The following tables are a reconciliation of net income (loss) to adjusted EBITDA for the years ended December 31, 2019, 2018 and 2017:
(1) Other, net includes the equity earnings from our investments, dividend income, income attributable to noncontrolling interests in subsidiaries, acquisition and transaction related costs including integration and severance, non-cash pension and post-retirement benefits and certain other miscellaneous items. (2) Includes all cash dividends and other cash distributions received from our investments.
Question:
What is the purpose of using EBITDA and adjusted EBITDA?
Answer: to evaluate operating performance and to facilitate the comparison of our historical results and trends.