SCHEDULE III (Details) - USD ($)
$ in Thousands

The estimated aggregate cost of real estate properties at December 31, 2019 for federal income tax purposes was approximately $3,179,014,000 before estimated accumulated tax depreciation of $619,405,000. The federal income tax return for the year ended December 31, 2019, has not been filed and accordingly, this estimate is based on preliminary data.



	Years Ended December 31,
	2019			2018		2017
	(In thousands)
Balance at beginning of year	$	2,817,145		2,578,748		2,407,029
Purchases of real estate properties	135,033			54,537		51,802
Development of real estate properties and value-add properties	318,288			167,667		124,938
Improvements to real estate properties	37,558			36,921		28,698
Right-of-use assets, net – ground leases	11,997			—		—
Carrying amount of investments sold	(51,662		)	(18,372	)	(32,787	)
Write-off of improvements	(3,793		)	(2,356	)	(932	)
Balance at end of year ⁽¹⁾	$	3,264,566		2,817,145		2,578,748

Includes noncontrolling interest in joint ventures of $3,148,000 and $3,296,000 at December 31, 2019 and 2018, respectively.

Changes in the accumulated depreciation on real estate properties follow:



	Years Ended December 31,
	2019			2018		2017
	(In thousands)
Balance at beginning of year	$	814,915		749,601		694,250
Depreciation expense	86,590			76,007		69,010
Accumulated depreciation on assets sold	(27,030		)	(8,670	)	(12,735	)
Other	(3,336		)	(2,023	)	(924	)
Balance at end of year	$	871,139		814,915		749,601

The Company computes depreciation using the straight-line method over the estimated useful lives of the buildings (generally 40 years) and improvements (generally 3 to 15 years).

EastGroup has a $37,682,000 non-recourse first mortgage loan with an insurance company secured by Arion 18, Beltway Crossing VI & VII, Commerce Park II & III, Concord, Interstate V-VII, Lakeview, Ridge Creek II, Southridge IV & V and World Houston 32.

The Company transfers properties from the development and value-add program to Real estate properties as follows: (i) for development properties, at the earlier of 90% occupancy or one year after completion of the shell construction, and (ii) for value-add properties, at the earlier of 90% occupancy or one year after acquisition. Upon the earlier of 90% occupancy or one year after completion of the shell construction, capitalization of development costs, including interest expense, property taxes and internal personnel costs, ceases and depreciation commences on the entire property (excluding the land).

EastGroup has a $44,596,000 non-recourse first mortgage loan with an insurance company secured by Colorado Crossing, Interstate I-III, Rojas, Steele Creek 1 & 2, Venture and World Houston 3-4 and 6-9.

Changes in mortgage loans follow:



	Years Ended December 31,
	2019			2018		2017
	(In thousands)
Balance at beginning of year	$	2,594		4,581		4,752
Payments on mortgage loans receivable	(915		)	(1,987	)	(171	)
Balance at end of year	$	1,679		2,594		4,581