Development of a Money Mismanagement Measure and cross-validation due to suspected range restriction.

A measure of the tendency to mismanage money was developed in an evaluation of a representative payee program for individuals with serious mental illnesses. A conceptual model was composed to guide item development, and items were tested, revised, added, and rejected in three waves of data collection. Rasch analyses were used to examine measurement properties. The resulting Money Mismanagement Measure (M3) consisted of 28 items with a Rasch person reliability at .72. Restriction of range was likely responsible for the low Rasch reliability. Validity analyses supported the construct validity of the M3. Subsequently, a cross-validation study was conducted on an untreated sample not as susceptible to range restriction. The M3 produced a Rasch person reliability = .85 with good validity. The M3 fills a gap that can facilitate research in the understudied area of money mismanagement.