Exhibit 12

ERP OPERATING LIMITED PARTNERSHIP
Computation of Ratio of Earnings to Combined Fixed Charges

	09/30/03			09/30/02		12/31/02		12/31/01		12/31/00		12/31/99		12/31/98
Income from continuing operations	$		207,976	$	218,442	$	328,394	$	395,030	$	363,319	$	306,523	$	236,112
Interest expense incurred, net	246,793			252,892		337,489		352,903		363,851		328,459		243,531
Amortization of deferred financing costs	4,406			4,267		5,748		5,818		5,432		4,024		2,724
Earnings before combined fixed charges and preferred distributions	459,175			475,601		671,631		753,751		732,602		639,006		482,367
Preferred distributions	73,115			72,969		97,151		106,119		111,941		113,196		92,917
Earnings before combined fixed charges	$	386,060		$	402,632	$	574,480	$	647,632	$	620,661	$	525,810	$	389,450
Interest expense incurred, net	$	246,793		$	252,892	$	337,489	$	352,903	$	363,851	$	328,459	$	243,531
Amortization of deferred financing costs	4,406			4,267		5,748		5,818		5,432		4,024		2,724
Interest capitalized for real estate and unconsolidated entities under development	16,013			19,444		27,167		28,174		17,650		8,134		1,620
Total combined fixed charges	267,212			276,603		370,404		386,895		386,933		340,617		247,875
Preferred distributions	73,115			72,969		97,151		106,119		111,941		113,196		92,917
Total combined fixed charges and preferred distributions	$	340,327		$	349,572	$	467,555	$	493,014	$	498,874	$	453,813	$	340,792
Ratio of earnings before combined fixed charges to total combined fixed charges	1.44			1.46		1.55		1.67		1.60		1.54		1.57
Ratio of earnings before combined fixed charges and preferred distributions to total combined fixed charges and preferred distributions	1.35			1.36		1.44		1.53		1.47		1.41		1.42