11. Deferred income tax

The movement in deferred tax assets and liabilities during the year was as follows:


	Assets	Liabilities	Total
	$m	$m	$m
At January 1, 2016	432	(729)	(297)
Acquisition (Note 22)	81	(243)	(162)
(Charged)/credited to the income statement (Note 6)	(46)	29	(17)
Credited/(charged) to other comprehensive income	20	(6)	14
Reclassification	3	(3)	—
Exchange	(21)	24	3
At December 31, 2016	469	(928)	(459)
(Charged)/credited to the income statement (Note 6)	(67)	207	140
(Charged)/credited to other comprehensive income	(6)	1	(5)
Reclassification	4	(4)	—
Exchange	28	(66)	(38)
At December 31, 2017	428	(790)	(362)

The components of deferred income tax assets and liabilities are as follows:


	At December 31,
	2017	2016
	$m	$m
Tax losses	34	34
Employee benefit obligations	187	181
Depreciation timing differences	90	86
Provisions	70	99
Other	47	69
	428	469
Available for offset	(207)	(196)
Deferred tax assets	221	273
Intangible assets	(395)	(508)
Accelerated depreciation and other fair value adjustments	(369)	(378)
Other	(26)	(42)
	(790)	(928)
Available for offset	207	196
Deferred tax liabilities	(583)	(732)

The tax credit/(charge) recognized in the consolidated income statement is analyzed as follows:


	Year ended December 31,
	2017	2016	2015
	$m	$m	$m
Tax losses	(2)	(3)	(19)
Employee benefit obligations	(21)	(13)	14
Depreciation timing differences	(6)	(13)	(2)
Provisions	(26)	—	(8)
Other deferred tax assets	(12)	(17)	21
Intangible assets	155	42	33
Accelerated depreciation and other fair value adjustments	29	(4)	19
Other deferred tax liabilities	23	(9)	(9)
	140	(17)	49

Deferred tax assets are only recognized on tax loss carry‑forwards to the extent that the realization of the related tax benefit through future taxable profits is probable based on management’s forecasts. The Group did not recognize deferred tax assets of $62 million (2016: $45 million) in respect of tax losses amounting to $373 million (2016: $235 million) that can be carried forward against future taxable income due to uncertainty regarding their utilization. In addition, the Group did not recognize deferred tax assets of $50 million (2016: $74 million) in respect of capital losses amounting to $239 million (2016: $212 million) that can be carried forward against future taxable income due to uncertainty regarding their utilization.

No provision has been made for temporary differences applicable to investments in subsidiaries as the Group is in a position to control the timing of reversal of the temporary difference and it is probable that the temporary difference will not reverse in the foreseeable future. Given that exemptions and tax credits would be available in the context of the Group’s investments in subsidiaries in the majority of jurisdictions in which it operates, the aggregate amount of temporary differences in respect of which deferred tax liabilities have not been recognized would not be material.