Final answer:
In accordance with USPAP, a Supervisory Appraiser without the necessary expertise and unwilling to obtain it must decline an assignment to appraise a complex property to maintain professional and ethical standards.
Step-by-step explanation:
When a Supervisory Appraiser is offered an assignment to appraise a complex property but lacks the necessary knowledge and experience, and does not wish to acquire it, the USPAP (Uniform Standards of Professional Appraisal Practice) requires the appraiser to decline the assignment. This is because USPAP emphasizes the importance of competence in assignment performance. Should the appraiser lack the requisite competence, they must either decline the assignment or take the necessary steps to attain competence, which could include acquiring the knowledge and experience prior to performing the assignment or arranging for assistance from a qualified appraiser who has the appropriate expertise.
In this scenario, since the Supervisory Appraiser does not want to invest time to become competent and cannot deliver a competent performance appraisal, it is essential according to USPAP to decline the assignment. This ensures that the appraisal is performed by someone with the appropriate level of competency and maintains the integrity and quality of the appraisal process. While this decision may disappoint the Trainee Appraiser looking forward to the learning opportunity, it is a necessary measure to uphold professional and ethical standards.