## Investments 

We hold equity investments in certain publicly-traded companies and privately held entities primarily involved in the life science industry.All of our investments in publicly-traded companies are considered “available for sale” in accordance with Statement of Financial Accounting Standards No. 115, “Accounting for Certain Investments in Debt and Equity Securities” (“SFAS 115”), and are recorded at fair value. Fair value has been determined as the closing trading price at the balance sheet date, with unrealized gains and losses shown as a separate component of stockholders’ equity.The classification of investments under SFAS 115 is determined at the time each investment is made, and such determina- tion is reevaluated at each balance sheet date.The cost of investments sold is determined by the specif- ic identification method, with realized gains and losses included in other income in the accompanying consolidated statements of income. 

Investments in privately held entities are generally accounted for under the cost method because we do not influence any operating or financial policies of the entities in which we invest. Certain invest- ments are accounted for under the equity method in accordance with Accounting Principles Board Opinion No. 18,“The Equity Method of Accounting for Investments in Common Stock” (“APB 18”) and Emerging Issues Task Force Topic D-46,“Accounting for Limited Partnership Investments” (“EITF Topic D-46”). Under the equity method we record our investment initially at cost and adjust the car- rying amount of the investment to recognize our share of the earnings or losses of the investee subse- quent to the date of our investment. 

For all of our investments, if a decline in the fair value of an investment below its carrying value is determined to be other than temporary, such investment is written-down to its estimated fair value with a non-cash charge to current earnings.The factors that we consider in making these assessments include, but are not limited to, market prices, market conditions, prospects for favorable or unfavorable clinical trial results, new product initiatives and new collaborative agreements. 

## Rental Properties and Properties Under Development 

In accordance with Statement of Financial Accounting Standards No. 141, “Business Combinations” , we perform the following procedures when making an allocation of the purchase price of real estate: (1) estimate the value of the real estate as of the acquisition date on an “as if vacant” basis; (2) allocate the “as if vacant” value among land, land improvements, buildings, building improvements, tenant improvements and equipment; (3) calculate the value of the intangibles as the difference between the “as if vacant” value and the purchase price; and (4) allocate the intangible value to above, below and at market leases, origination costs associated with in-place leases, tenant relationships and other intangi- ble assets. 

The values allocated to land improvements, buildings, building improvements, tenant improvements and equipment are depreciated on a straight-line basis using an estimated life of 20 years for land improvements, 40 years for buildings and building improvements, the respective lease term for tenant improvements and the estimated useful life for equipment.The values of above and below market leas- es are amortized over the life of the related lease and recorded as either an increase (for below market leases) or a decrease (for above market leases) to rental income.The values of at-market leases and orig- ination costs are classified as leasing costs, included in other assets in the accompanying consolidated bal- ance sheets and amortized over the remaining life of the lease. 

Rental properties and properties under development are individually evaluated for impairment when conditions exist which may indicate that it is probable that the sum of expected future undiscounted cash flows is less than the carrying amount of the property. Upon determination that an impairment has occurred, a write-down is recorded to reduce the carrying amount of the property to its estimated fair value. 

In accordance with Statement of Financial Accounting Standards No. 34, “Capitalization of Interest Cost” (“SFAS 34”) and Statement of Financial Accounting Standards No. 67,“Accounting for Costs and Initial Rental Operations of Real Estate Projects” (“SFAS 67”), we capitalize direct construction and development costs, including predevelopment costs, interest, property taxes, insurance and other costs directly related and essential to the acquisition, development or construction of a project. Pursuant to 

