Which method of calculating depreciation assumes that depreciation occurs at an even rate?

The economic age-life method is the correct choice because it operates on the principle that a property's value decreases evenly over its useful life. This method assumes that the wear and tear on a property happens in a consistent and predictable manner, allowing for depreciation to be calculated as a straight-line deduction over time. This approach makes it easier for appraisers and investors to estimate how much value a property has lost due to age and use.

In contrast, other methods like the declining balance method result in larger depreciation amounts in the earlier years and smaller amounts later on, as they apply a constant percentage to the remaining book value. The market value method focuses on current market trends and values rather than a systematic approach to depreciation. Finally, the reproduction cost method estimates the cost to replicate the property anew, considering factors like materials and labor, rather than focusing solely on depreciation. Each of these methods serves a different purpose and reflects different principles of valuation, which is why the economic age-life method is uniquely suited for assuming an even rate of depreciation.