The following table provides our income before income taxes and  equity in net income of unconsolidated entities, generated by our  U.S. and non-U.S. operations: The deferred tax assets and liabilities are included in our Consolidated  Balance Sheets as follows: We recognize deferred income taxes for the temporary differences  between the carrying amount of assets and liabilities for financial  statement purposes and their tax basis. The tax effects of the tem- porary differences that give rise to the deferred income tax assets  and liabilities are as follows: The following table summarizes our U.S. NOL carryforwards: Morningstar, Inc. 2010 Annual Report 133 Deferred Tax Assets and Liabilities Deferred Tax Assets and Liabilities ($000)  2010 2009  2008 U.S.  $ 112,357 $123,948  $135,997 Non-U.S.  15,434 3,659  7,131 Income before income taxes  $ 127,791 $127,607  $143,128 and equity in net income of unconsolidated entities As of December 31 ($000)  2010 2009 Deferred tax asset, net—current  $  2,860 $  1,109 Deferred tax liability, net—non-current (19,975)  (14,640) Net deferred tax liability  $ (17,115) $ (13,531) As of December 31 ($000)  2010 2009 U.S. NOLs subject to  $2,811 $5,084 expiration dates  Expiration date  2023  2023–2029 As of December 31 ($000) 2010 2009 Deferred tax assets: Stock-based compensation expense  $ 7,859 $ 12,936 Accrued liabilities  5,728 6,263 Net operating loss carryforwards—U.S.  1,087 1,933 Net operating loss carryforwards—Non-U.S. 12,977 14,022 Research and development  — 253 Deferred royalty revenue  430 470 Allowance for doubtful accounts  461 533 Deferred rent  8,837 9,929 Other  185 161 Total deferred tax assets  37,564  46,500 Deferred tax liabilities: Acquired intangible assets  (22,287)  (26,034) Property, equipment, and capitalized software  (8,439) (9,086) Unrealized exchange gains, net  (529) (258) Prepaid expenses  (1,856) (2,833) Accrued liabilities  (578) (1,322) Investments in unconsolidated entities  (9,471) (7,600) Other  (95) (64) Total deferred tax liabilities  (43,255)  (47,197) Net deferred tax liability before valuation allowance  (5,691) (697) Valuation allowance  (11,424)  (12,834) Net deferred tax liability  $ (17,115) $ (13,531)