market risk management 2013 equity and other investment equity investment risk is the risk of potential losses associated with investing in both private and public equity markets . in addition to extending credit , taking deposits , securities underwriting and trading financial instruments , we make and manage direct investments in a variety of transactions , including management buyouts , recapitalizations and growth financings in a variety of industries . we also have investments in affiliated and non-affiliated funds that make similar investments in private equity and in debt and equity-oriented hedge funds . the economic and/or book value of these investments and other assets such as loan servicing rights are directly affected by changes in market factors . the primary risk measurement for equity and other investments is economic capital . economic capital is a common measure of risk for credit , market and operational risk . it is an estimate of the potential value depreciation over a one year horizon commensurate with solvency expectations of an institution rated single-a by the credit rating agencies . given the illiquid nature of many of these types of investments , it can be a challenge to determine their fair values . see note 7 fair value in the notes to consolidated financial statements in item 8 of this report for additional information . various pnc business units manage our equity and other investment activities . our businesses are responsible for making investment decisions within the approved policy limits and associated guidelines . a summary of our equity investments follows : table 54 : equity investments summary in millions december 31 december 31 .
for tax credit investments included in our equity investments held by consolidated partnerships , what was the change in billions between december 31 , 2014 and december 31 , 2013?
( a ) the december 31 , 2013 amount has been updated to reflect the first quarter 2014 adoption of asu 2014-01 related to investments in low income housing tax credits . blackrock pnc owned approximately 35 million common stock equivalent shares of blackrock equity at december 31 , 2014 , accounted for under the equity method . the primary risk measurement , similar to other equity investments , is economic capital . the business segments review section of this item 7 includes additional information about blackrock . tax credit investments included in our equity investments are direct tax credit investments and equity investments held by consolidated partnerships which totaled $ 2.6 billion at both december 31 , 2014 and december 31 , 2013 . these equity investment balances include unfunded commitments totaling $ 717 million and $ 802 million at december 31 , 2014 and december 31 , 2013 , respectively . these unfunded commitments are included in other liabilities on our consolidated balance sheet . note 2 loan sale and servicing activities and variable interest entities in the notes to consolidated financial statements in item 8 of this report has further information on tax credit investments . private equity the private equity portfolio is an illiquid portfolio comprised of mezzanine and equity investments that vary by industry , stage and type of investment . private equity investments carried at estimated fair value totaled $ 1.6 billion at december 31 , 2014 and $ 1.7 billion at december 31 , 2013 . as of december 31 , 2014 , $ 1.1 billion was invested directly in a variety of companies and $ .5 billion was invested indirectly through various private equity funds . included in direct investments are investment activities of two private equity funds that are consolidated for financial reporting purposes . the noncontrolling interests of these funds totaled $ 212 million as of december 31 , 2014 . the interests held in indirect private equity funds are not redeemable , but pnc may receive distributions over the life of the partnership from liquidation of the underlying investments . see item 1 business 2013 supervision and regulation and item 1a risk factors of this report for discussion of the potential impacts of the volcker rule provisions of dodd-frank on our interests in and sponsorship of private funds covered by the volcker rule . our unfunded commitments related to private equity totaled $ 140 million at december 31 , 2014 compared with $ 164 million at december 31 , 2013 . the pnc financial services group , inc . 2013 form 10-k 93 .