CP 2019 ANNUAL REPORT /  86 6. Income taxes The following is a summary of the major components of the Company’s income tax expense: The provision for deferred income taxes arises from temporary differences in the carrying values of assets and liabilities for financial statement and income tax purposes and the effect of loss carry forwards. The items comprising the deferred income tax assets and liabilities are as follows: (in millions of Canadian dollars) 2019 2018 2017 Current income tax expense $ 525 $ 381 $ 303 Deferred income tax expense Origination and reversal of temporary differences 316 214 371 Effect of tax rate decrease (95) (21) (541) Effect of hedge of net investment in foreign subsidiaries (38 ) 64 (42 ) Other (2) (1) 2 Total deferred income tax expense (recovery) 181 256 (210 ) Total income taxes $ 706 $ 637 $ 93 Income before income tax expense Canada $ 2,392 $ 1,788 $ 1,829 Foreign 754 800 669 Total income before income tax expense $ 3,146 $ 2,588 $ 2,498 Income tax expense Current Canada $ 410 $ 336 $ 257 Foreign 115 45 46 Total current income tax expense 525 381 303 Deferred Canada 141 174 256 Foreign 40 82 (466) Total deferred income tax expense (recovery) 181 256 (210 ) Total income taxes $ 706 $ 637 $ 93 (in millions of Canadian dollars) 2019 2018 Deferred income tax assets Amount related to tax losses carried forward $ 6 $ 11 Liabilities carrying value in excess of tax basis 139 97 Unrealized foreign exchange losses 26 85 Environmental remediation costs 22 23 Other 4 2 Total deferred income tax assets 197 218 Valuation allowance — (5) Total net deferred income tax assets 197 213 Deferred income tax liabilities Properties carrying value in excess of tax basis 3,524 3,496 Pensions carrying value in excess of tax basis 83 164 Other 91 71 Total deferred income tax liabilities 3,698 3,731 Total net deferred income tax liabilities $ 3,501 $ 3,518