(13) Segment Information TripCo, through its ownership interests in subsidiaries and other companies, is primarily engaged in the online commerce industries. TripCo identifies its reportable segments as (A) those consolidated companies that represent 10% or more of its consolidated annual revenue, annual adjusted operating income before depreciation and amortization (Adjusted OIBDA) or total assets and (B) those equity method affiliates whose share of earnings represent 10% or more of TripCos annual pre-tax earnings. TripCo evaluates performance and makes decisions about allocating resources to its operating segments based on financial measures such as revenue, Adjusted OIBDA, gross margin, average sales price per unit, number of units shipped and revenue or sales per customer equivalent. In addition, TripCo reviews nonfinancial measures such as unique website visitors, conversion rates and active customers, as appropriate. TripCo defines Adjusted OIBDA as revenue less operating expenses, and selling, general and administrative expenses (excluding stock-based compensation), adjusted for specifically identified non-recurring transactions. TripCo believes this measure is an important indicator of the operational strength and performance of its businesses, including each businesss ability to service debt and fund capital expenditures. In addition, this measure allows management to view operating results and perform analytical comparisons and benchmarking between businesses and identify strategies to improve performance. This measure of performance excludes depreciation and amortization, equity settled liabilities (including stock-based compensation), separately reported litigation settlements and restructuring and impairment charges that are included in the measurement of operating income pursuant to GAAP. Accordingly, Adjusted OIBDA should be considered in addition to, but not as a substitute for, operating income, net income, cash flow provided by operating activities and other measures of financial performance prepared in accordance with GAAP. TripCo generally accounts for intersegment sales and transfers as if the sales or transfers were to third parties, that is, at current prices. For the year ended December 31, 2018, TripCo has identified the following consolidated company as its reportable segment:  TripAdvisor - an online travel research company, empowering consumers to plan and maximize their travel experience. TripCos operating segments are strategic business units that offer different products and services. They are managed separately because each segment requires different technologies, distribution channels and marketing strategies. The accounting policies of the segments that are also consolidated companies are the same as those described in the Companys summary of significant accounting policies. Performance Measures Years ended December 31, 2018 2017 2016 Adjusted Adjusted Adjusted Revenue OIBDA Revenue OIBDA Revenue OIBDA amounts in millions TripAdvisor $ 1,615 422 1,556 331 1,480 352 Corporate and other  (6) 13 (9) 52 (16) Consolidated TripCo $ 1,615 416 1,569 322 1,532 336 Other Information December 31, 2018 December 31, 2017 Total Capital Total Capital Assets expenditures Assets expenditures amounts in millions TripAdvisor $ 5,187 61 5,387 64 Corporate and other 37  97 1 Consolidated TripCo $ 5,224 61 5,484 65 Revenue by Geographic Area During the fourth quarter of 2018, the Company revised the basis in which it measures geographic revenue information to the physical location of the TripAdvisor subsidiary which generates the revenue, which is consistent with the measurement of long-lived physical assets, or property and equipment, net. All prior periods have been reclassified to conform to the current period presentation. These reclassifications had no effect on our consolidated financial statements. December 31, 2018 2017 2016 amounts in millions United States $ 835 815 770 United Kingdom 508 530 564 Other countries 272 224 198 Consolidated TripCo $ 1,615 1,569 1,532 Long-lived Assets by Geographic Area December 31, 2018 2017 amounts in millions United States $ 137 147 Other countries 17 18 Consolidated TripCo $ 154 165 The following table provides a reconciliation of consolidated Adjusted OIBDA to operating income and earnings (loss) before income taxes: Years ended December 31, 2018 2017 2016 amounts in millions Consolidated Adjusted OIBDA $ 416 322 336 Legal settlement (5)   Stock-based compensation (123) (103) (91) Depreciation and amortization (160) (213) (222) Impairment of intangible assets  (1,798)  Operating income 128 (1,792) 23 Interest expense (26) (25) (25) Realized and unrealized gains (losses) on financial instruments, net (59) 24 53 Gain (loss) on dispositions, net  (18)  Other, net 5 1 (5) Earnings (loss) before income taxes $ 48 (1,810) 46