Which of the following would a property manager include in a list of operating expenses?

The vacancy rate is a measure of the percentage of rental units that are unoccupied at a given time. While it is an important metric for assessing property performance, it is not an expense incurred by the property manager. Instead, it reflects potential income loss due to unoccupied units.

Depreciation is an accounting method used to allocate the cost of tangible assets over their useful lives. While it is a financial consideration for property owners, it is not a cash expense that affects the property's day-to-day operations. Therefore, it does not belong on a list of operating expenses.

Mortgage payments consist of principal and interest payments made to a lender, which are considered financing costs rather than operational expenses. Although relevant to overall financial management, these payments do not fall under the category of regular operating expenses incurred in managing the property.