An appraiser valuing a single-unit dwelling uses a file of comparable sales from a report the appraiser completed 10 months earlier, and uses those comps to value the subject without conducting any new research. What type of bias is demonstrated?

• A. Availability bias
• B. Confirmation bias
• C. Hindsight bias
• D. Anchoring bias

Answer: (A)

Relying on information that is readily available rather than seeking new data is the key idea here. The appraiser used comparable sales from a report completed 10 months earlier and did not perform any new research to check current market conditions. This shows availability bias—relying on the comps that are most easily accessible in the file instead of gathering up-to-date evidence.

This differs from confirmation bias, which would involve selecting information to prove a preconceived valuation; hindsight bias, which would treat past events as having been predictable after the fact; and anchoring bias, which would fixate on an initial number and not adjust adequately. The scenario’s main issue is the overreliance on readily available, outdated data rather than actively updating with current market data, which is why availability bias is the best fit.