Our effective income tax rate differs from the federal statutory rate due to the following: Income before provision for income taxes for the years ended December 31, 2013, 2012 and 2011 is as follows: Income before provision for income taxes for international entities reflects income based on statutory transfer pricing  agreements. This amount does not correlate to consolidated international revenues, many of which occur from our U.S. entity. Deferred income taxes on the balance sheet result from temporary differences between the amount of assets and liabilities  recognized for financial reporting and tax purposes. The principal components of our current and non-current deferred taxes  are as follows: ADTRAN 2013 Annual Report 58 (In thousands)  2013 2012 Current deferred tax assets Accounts receivable $51 $2 Inventory 9,877 7,507 Accrued expenses 7,155 5,546 Total Current Deferred Tax Assets 17,083 13,055 Non-current deferred tax assets Accrued expenses 140 116 Deferred compensation 5,972 4,456 Stock-based compensation 5,331 4,569 Uncertain tax positions related to state taxes and related interest 1,107 1,005 Pensions 301 605 Foreign losses  5,702 6,978 State losses and credit carry-forwards 3,737 4,349 Federal loss and research carry-forwards 8,322 12,210 Valuation allowance (8,842) (10,939) Total Non-current Deferred Tax Assets 21,770 23,349 Total Deferred Tax Assets $38,853 $36,404 Non-current Deferred Tax Liabilities Property, plant and equipment $(5,499) $(6,405) Intellectual property (1,006) (1,839) Investments (5,643) (4,844) Total Non-current Deferred Tax Liabilities $(12,148) $(13,088) Net Deferred Tax Assets  $26,705 $23,316 (In thousands)  2013 2012 2011 U.S. entities $51,752 $80,926 $204,652 International 9,103 (7,961) 1,490 Total $60,855 $72,965 $206,142 2013 2012 2011 Tax provision computed at the federal statutory rate  35.00% 35.00% 35.00% State income tax provision, net of federal benefit 3.98 3.78 3.19 Federal research credits (9.24) — (2.50) International (2.93) 3.80 — Tax-exempt income (1.11) (1.01) (0.27) State tax incentives (2.19) (4.46) (0.90) Stock-based compensation 2.97 2.36 0.03 Domestic production activity deduction (1.80) (3.21) (1.84) Other, net 0.07 (1.03) 0.07 Effective Tax Rate 24.75% 35.23% 32.78%