1 EXHIBIT 11.1 ESSEX PORTFOLIO, L.P. STATEMENT OF COMPUTATION OF EARNINGS PER UNIT (Dollars in thousands except per unit amounts) QUARTER ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, ---------------------------- ------------------------------ 1998 1997 1998 1997 ------------ ------------ ------------ ------------ BASIC: Net income $ 9,096 $ 12,485 $ 28,527 $ 25,247 Less: Distributions on Preferred Interest for 8.75% Series 1996A Convertible Preferred Stock (875) (875) (2,625) (1,805) Distributions on 7.875% Series B Cumulative Redeemable Preferred Units (1,575) -- (3,789) -- ------------ ------------ ------------ ------------ Net income applicable to general and limited partners $ 6,646 $ 11,610 $ 22,113 $ 23,442 ============ ============ ============ ============ Weighted average number of units outstanding during the period 18,508,701 15,789,263 18,502,194 14,885,921 ============ ============ ============ ============ Net income per partnership unit $ 0.36 $ 0.74 $ 1.20 $ 1.57 ============ ============ ============ ============ DILUTED: Adjusted units - basic, from above 18,508,701 15,789,263 18,502,194 14,885,921 Additional weighted average units of dilutive stock options using the average stock price under the treasury stock method 186,193 217,565 186,159 205,689 Additional weighted average units issuable upon conversion of 8.75% Convertible Preferred Stock, Series 1996A(1) - 1,828,572 - 1,255,887 ------------ ------------ ------------ ------------ Weighted average number of units outstanding during the period 18,694,894 17,835,400 18,688,353 16,347,497 ============ ============ ============ ============ Net income per partnership unit(2) $ 0.36 $ 0.70 $ 1.18 $ 1.54 ============ ============ ============ ============ - ------------------- (1) In accordance with Statement of Accounting Standards Board No. 128, the additional weighted average units issuable upon conversion of the 8.75% Convertible Preferred Stock, Series 1996A is not included for the three and nine months ended September 30, 1998 as the effect would be anti-dilutive. (2) In accordance with Statement of Accounting Standards Board No. 128, preferred distributions were included in the numerator of net income per unit for the three and nine months ended September 30, 1997 as the additional weighted average units issuable upon conversion of the 8.75% Convertible Preferred Stock, Series 1996A was dilutive.