|We consistently use the below non-GAAP financial measures to evaluate the results of our operations. We believe that the presentation of these non-GAAP measures provides useful information to investors regarding financial and business trends related to our results of operations and that when this non-GAAP financial information is viewed with our GAAP financial information, investors are provided with a more meaningful understanding of our ongoing operating performance. None of the non-GAAP measures presented should be considered as an alternative to net income or loss, operating income or loss, cash flows from operating activities or any other performance measures of operating performance or liquidity derived in accordance with GAAP. These non-GAAP measures have important limitations as analytical tools and should not be considered in isolation or as substitutes for an analysis of our results as reported under GAAP.
The following is a list of non-GAAP financial measures which Nielsen has discussed or expects to discuss in the future:
Constant Currency Presentation
We evaluate our results of operations on both an as reported and a constant currency basis. The constant currency presentation, which is a non-GAAP measure, excludes the impact of fluctuations in foreign currency exchange rates. We believe providing constant currency information provides valuable supplemental information regarding our results of operations, consistent with how we evaluate our performance. We calculate constant currency percentages by converting our prior-period local currency financial results using the current period exchange rates and comparing these adjusted amounts to our current period reported results.
Net Debt and Net Debt Leverage Ratio
The net debt leverage ratio is defined as net debt as of the balance sheet date divided by Adjusted EBITDA for the twelve months then ended. Net debt and the net debt leverage ratio are not presentations made in accordance with GAAP, and our use of these terms may vary from the use of similarly-titled measures by others in our industry due to the potential inconsistencies in the method of calculation and differences due to items subject to interpretation.
We define Adjusted EBITDA as net income or loss from our consolidated statements of operations before interest income and expense, income taxes, depreciation and amortization, restructuring charges, goodwill and intangible asset impairment charges, stock compensation expense and other non-operating items from our consolidated statements of operations as well as certain other items considered unusual or non-recurring in nature. Adjusted EBITDA is not a presentation made in accordance with GAAP, and our use of the term Adjusted EBITDA may vary from the use of similarly-titled measures by others in our industry due to the potential inconsistencies in the method of calculation and differences due to items subject to interpretation. We use Adjusted EBITDA to consistently measure our performance from period to period both at the consolidated level as well as within our operating segments, to evaluate and fund incentive compensation programs and to compare our results to those of our competitors.
Adjusted Net Income
We define Adjusted Net Income as net income or loss from our consolidated statements of operations before income taxes, depreciation and amortization associated with acquired tangible and intangible assets, restructuring charges, goodwill and intangible asset impairment charges, other non-operating items from our consolidated statements of operations and certain other items considered unusual or non-recurring in nature, reduced by cash paid for income taxes. Also excluded from Adjusted Net Income is interest expense attributable to the mandatory convertible subordinated bonds due 2013.
2Q13 Non-GAAP Reconciliations