Year Ended December 31 2008  2009 2010 NT$ NT$ NT$ (In Millions) Income tax payable $  13,667  $  11,777  $  9,100  Income tax - separated 303  63  4  Income tax - deferred (156) 1,099  27  Adjustments of prior years’ income tax 78  (196) (2) $  13,892  $  12,743  $  9,129  In May 2010, the Legislative Yuan passed the amendment of Article 5 of the Income Tax Law, which  reduced the income tax rate of profit-seeking enterprises to 17%, effective from January 1, 2010. The  Company recalculated its deferred income tax assets and liabilities in accordance with the amended  Article and recorded the resulting difference as an income tax expense or benefit.  Under Article 10 of the Statute for Industrial Innovation (SII) passed by the Legislative Yuan in April  2010, a profit-seeking enterprise may deduct up to 15% of its research and development expenditures  from its income tax payable for the fiscal year in which these expenditures are incurred, but this deduction  should not exceed 30% of the income tax payable for that fiscal year. This incentive took effect from  January 1, 2010 and is effective until December 31, 2019.  d. Deferred income taxes arise due to temporary differences in the book and tax bases of certain assets and  liabilities. Significant components of deferred income tax assets are shown in the following table:  The decrease of valuation allowance as of December 31, 2010 was attributed to the change of provision for  doubtful accounts.  December 31 2009 2010 NT$ NT$ (In Millions) Current Deferred income tax assets (liabilities): Provision for doubtful accounts $  351  $  241  Unrealized accrued expense 50  51  Estimated warranty liabilities 19  23  Valuation loss on inventory 17  17  Investment tax credit 1  2  Unrealized foreign exchange loss 3  1  Loss carryforward 2  —  Valuation gain on financial instruments, net (9) (6) Others 18  3  452  332  Valuation allowance (351) (241) Net deferred income tax assets - current $  101  $  91  December 31 2009 2010 NT$ NT$ (In Millions) Noncurrent Accrued pension cost $  333  $  296  Loss carryforward 113  78  Impairment loss 64  64  Abandonment of equipment not approved by National Tax  Administration — 38  Investment tax credit 17  14  Equity in losses of equity method investees, net — 6  Others 16  3  543  499  Valuation allowance (60) (27) Net deferred income tax assets - noncurrent $  483  $  472  F-44