**Exhibit 12**

**ERP OPERATING LIMITED PARTNERSHIP**

**Computation of Ratio of Earnings to CombinedFixed Charges**

 
|                                                                                                                                          |   | **06/30/03** |        | **06/30/02** |       | **12/31/02** |       | **12/31/01** |        | **12/31/00** |       | **12/31/99** |       | **12/31/98** |        |
|-----------------------------------------------------------------------------------------------------------------------------------------------|--------|--------------|-------------|--------------|------------|--------------|------------|--------------|-------------|--------------|------------|--------------|------------|--------------|-------------|
| Income from continuing operations                                                                                                             |   | $            | 145,680     |         | $          | 175,327      |       | $            | 328,394     |         | $          | 395,030      |       | $            | 363,319     |   | $ | 306,523 |   | $ | 236,112 |   |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| Interest and other financing costs                                                                                                            |   | 164,532      |        | 170,528      |       | 337,489      |       | 352,903      |        | 363,851      |       | 328,459      |       | 243,531      |        |
| Amortization of deferred financing costs                                                                                                      |   | 3,104        |        | 2,962        |       | 5,748        |       | 5,818        |        | 5,432        |       | 4,024        |       | 2,724        |        |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| **Earnings before combined fixed charges and preferred  distributions**                                                                       |   | **313,316**  | ** **  | **348,817**  | ** ** | **671,631**  | ** ** | **753,751**  | ** **  | **732,602**  | ** ** | **639,006**  | ** ** | **482,367**  | ** **  |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| Preferred distributions                                                                                                                       |   | 48,417       |        | 48,781       |       | 97,151       |       | 106,119      |        | 111,941      |       | 113,196      |       | 92,917       |        |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| **Earnings before combined fixed charges**                                                                                                    |   | **$**        | **264,899** | ** **   | **$**      | **300,036**  | ** ** | **$**        | **574,480** | ** **   | **$**      | **647,632**  | ** ** | **$**        | **620,661** | ** ** | **$** | **525,810** | ** ** | **$** | **389,450** | ** ** |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| Interest and other financing costs                                                                                                            |   | $            | 164,532     |         | $          | 170,528      |       | $            | 337,489     |         | $          | 352,903      |       | $            | 363,851     |   | $ | 328,459 |   | $ | 243,531 |   |
| Amortization of deferred financing costs                                                                                                      |   | 3,104        |        | 2,962        |       | 5,748        |       | 5,818        |        | 5,432        |       | 4,024        |       | 2,724        |        |
| Interest capitalized for real estate and unconsolidated entities  under development                                                           |   | 10,923       |        | 12,323       |       | 27,167       |       | 28,174       |        | 17,650       |       | 8,134        |       | 1,620        |        |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| **Total combined fixed charges**                                                                                                              |   | **178,559**  | ** **  | **185,813**  | ** ** | **370,404**  | ** ** | **386,895**  | ** **  | **386,933**  | ** ** | **340,617**  | ** ** | **247,875**  | ** **  |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| Preferred distributions                                                                                                                       |   | 48,417       |        | 48,781       |       | 97,151       |       | 106,119      |        | 111,941      |       | 113,196      |       | 92,917       |        |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| **Total combined fixed charges and****preferred distributions**                                                                               |   | **$**        | **226,976** | ** **   | **$**      | **234,594**  | ** ** | **$**        | **467,555** | ** **   | **$**      | **493,014**  | ** ** | **$**        | **498,874** | ** ** | **$** | **453,813** | ** ** | **$** | **340,792** | ** ** |
|                                                                                                                                          |   |         |        |         |       |         |       |         |        |         |       |         |       |         |        |
| **Ratio of earnings before combined fixed charges to  total combined fixed charges**                                                          |   | **1.48**     | ** **  | **1.61**     | ** ** | **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** |   | **1.38**     | ** **  | **1.49**     | ** ** | **1.44**     | ** ** | **1.53**     | ** **  | **1.47**     | ** ** | **1.41**     | ** ** | **1.42**     | ** **  |
|                                                                                                                                               |        |              |             |              |            |              |            |              |             |              |            |              |            |              |             |  |  |  |  |  |  |  |  |

 

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