7. Equity

During the three months ended March 31, 2015, five limited partners exchanged 483,154 units for an equal number of shares of common stock of Simon pursuant to our partnership agreement. This transaction increased Simon's ownership interest in us.

On April 2, 2015, the Simon Board of Directors authorized a common stock repurchase program under which Simon may purchase up to $2.0 billion of its common stock over the next twenty-four months as market conditions warrant. Simon may repurchase the shares in the open market or in privately negotiated transactions.

Stock Based Compensation

Awards under our stock based compensation plans primarily take the form of LTIP units and restricted stock grants made under our 1998 Stock Incentive Plan, as amended, or the Plan. Restricted stock and awards under the LTIP programs are all performance based and are based on various corporate and business unit performance measures as further described below. The expense related to these programs, net of amounts capitalized, is included within home and regional office costs and general and administrative costs in the accompanying consolidated statements of operations and comprehensive income.

LTIP Programs. Every year since 2010, the Compensation Committee of Simon's Board of Directors, or Compensation Committee, has approved long-term, performance based incentive compensation programs, or the LTIP programs, for certain senior executive officers. Awards under the LTIP programs take the form of LTIP units, a form of limited partnership interest issued by us, and will be considered earned if, and only to the extent to which, applicable total shareholder return, or TSR, performance measures are achieved during the performance period. Once earned, LTIP units are subject to a two year vesting period. One-half of the earned LTIP units will vest on January 1 of each of the 2nd and 3rd years following the end of the applicable performance period, subject to the participant maintaining employment with us through those dates and certain other conditions as described in those agreements. Awarded LTIP units not earned are forfeited. Earned and fully vested LTIP units are the equivalent of units. During the performance period, participants are entitled to receive distributions on the LTIP units awarded to them equal to 10% of the regular quarterly distributions paid on a unit. As a result, we account for these LTIP units as participating securities under the two-class method of computing earnings per unit.

From 2010 to 2015, Simon's Compensation Committee approved LTIP grants as shown in the table below. Grant date fair values of the LTIP units are estimated using a Monte Carlo model, and the resulting expense is recorded regardless of whether the TSR performance measures are achieved if the required service is delivered. The grant date fair values are being amortized into expense over the period from the grant date to the date at which the awards, if any, would become vested. The extent to which LTIP units were earned, and the aggregate grant date fair values adjusted for estimated forfeitures, are as follows:

LTIP Program	LTIP Units Earned	Grant Date Fair Value
2010 LTIP Program
1-year 2010 LTIP Program	133,673	1-year program — $7.2 million
2-year 2010 LTIP Program	337,006	2-year program — $14.8 million
3-year 2010 LTIP Program	489,654	3-year program — $23.0 million
2011-2013 LTIP Program	469,848	$35.0 million
2012-2014 LTIP Program	401,203	$35.0 million
2013-2015 LTIP Program	To be determined in 2016	$29.5 million
2014-2016 LTIP Program	To be determined in 2017	$30.0 million
2015-2017 LTIP Program	To be determined in 2018	$29.9 million

We recorded compensation expense, net of capitalization, related to these LTIP programs of approximately $6.2 million and $6.8 million for the three months ended March 31, 2015 and 2014, respectively.

Restricted Stock. We recorded compensation expense, net of capitalization, related to restricted stock of approximately $2.1 million and $2.7 million, for the three months ended March 31, 2015 and 2014, respectively.

Other Compensation Arrangements. On July 6, 2011, in connection with the execution of an eight year employment agreement, the Compensation Committee granted David Simon, Simon's Chairman and CEO, a retention award in the form of 1,000,000 LTIP units, or the Award, for his continued service as Simon's Chairman and Chief Executive Officer through July 5, 2019. Effective December 31, 2013, the Award was modified, or the Current Award, and as a result the LTIP units will now become earned and eligible to vest based on the attainment of Company-based performance goals, in addition to the service-based vesting requirement included in the original Award. If the relevant performance criteria are not achieved, all or a portion of the Current Award will be forfeited. The Current Award does not contain an opportunity for Mr. Simon to receive additional LTIP Units above and beyond the original Award should Simon's performance exceed the higher end of the performance criteria. The performance criteria of the Current Award are based on the attainment of specific funds from operations, or FFO, per share. If the performance criteria have been met, a maximum of 360,000 LTIP units, or the A Units, 360,000 LTIP units, or the B Units, and 280,000 LTIP units, or the C Units, may become earned December 31, 2015, 2016 and 2017, respectively. The earned A Units will vest on January 1, 2018, earned B Units will vest on January 1, 2019 and earned C Units will vest on June 30, 2019, subject to Mr. Simon's continued employment through such applicable date. The grant date fair value of the retention award of $120.3 million is being recognized as expense over the eight-year term of his employment agreement on a straight-line basis through the applicable vesting periods of the A Units, B Units and C Units.

Changes in Equity

The following table provides a reconciliation of the beginning and ending carrying amounts of total equity, equity attributable to partners and equity attributable to noncontrolling interests:

	Preferred Units			Simon (Managing General Partner)			Limited Partners			Noncontrolling interests			Total Equity
January 1, 2015	$	44,062		$	5,049,115		$	858,557		$	(229	)	$	5,951,505
Limited partner units exchanged to units					7,849			(7,849	)					—
LTIP units								11,828						11,828
Purchase and disposition of noncontrolling interests, net and other		(82	)		(5,730	)					183			(5,629	)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership					5,598			(5,598	)					—
Distributions to limited partners, excluding preferred interests classified as temporary equity		(834	)		(435,777	)		(73,538	)		(1,372	)		(511,521	)
Comprehensive income, excluding $479 attributable to preferred distributions on temporary equity preferred units		834			448,344			75,939			690			525,807

March 31, 2015	$	43,980		$	5,069,399		$	859,339		$	(728	)	$	5,971,990