6. Income Taxes

Effective Income Tax Rate

Our provision for income taxes may not have the customary relationship of taxes to income. A reconciliation between the U.S. corporate income tax rate and the effective income tax rate was as follows:

	For the three months ended		For the nine months ended
	September 30,		September 30,
	2017	2016	2017	2016
U.S. corporate income tax rate	35 %	35 %	35 %	35 %
Dividends received deduction	(4)	(11)	(7)	(10)
Tax credits	(2)	(4)	(2)	(2)
Impact of equity method presentation	(1)	(3)	(2)	(3)
Local country permanent tax adjustments	(1)	(2)	(1)	(1)
Interest exclusion from taxable income	(1)	(2)	(1)	(1)
Impact of noncontrolling interest presentation	—	(2)	—	(1)
State income taxes	4	—	2	—
Other	—	1	—	(2)

Effective income tax rate	30 %	12 %	24 %	15 %

Unrecognized Tax Benefits

A summary of the changes in unrecognized tax benefits follows:

	For the nine months ended		For the year ended
	September 30, 2017		December 31, 2016
	(in millions)
Balance at beginning of period	$	207.8	$	219.0
Additions based on tax positions related to the current year	7.0		0.8
Additions for tax positions of prior years	19.3		0.8
Reductions for tax positions related to the current year	(0.3)		(12.6)
Reductions for tax positions of prior years	(0.5)		(0.2)
Settlements	(36.7)		—

Balance at end of period (1)	$	196.6	$	207.8

(1)

Of this amount, $44.4 million, if recognized, would reduce the 2017 effective income tax rate. We recognize interest and penalties related to uncertain tax positions in operating expenses.

As of September 30, 2017 and December 31, 2016, we had recognized $124.3 million and $142.4 million of accumulated pre-tax interest and penalties related to unrecognized tax benefits, respectively.