The relationships between student achievement, school district economies of scale, school district size and student socioeconomic status were measured for 131 school districts in the state of Oregon. Data for school districts ranging in size from districts with around 300 students to districts with more than 40,000 students were collected for cohort graduation rate, dollars spent per graduate, district size, and student socioeconomic status. Three statistical analyses were conducted including a zero-order correlation, partial correlation, and a multiple regression to answer five formal hypotheses advanced regarding the relationships between these factors.

The five formal hypotheses were formed based upon the researcher’s previously untested and unpublished structural deficiency theory. Four of the five formal hypotheses were supported. First, increased district size was found to significantly associated with lower academic achievement. Second, low student socioeconomic status was correlated with decreased academic achievement. Third, increased district size acting in concert with low student socioeconomic status was associated with even lower student academic achievement than posted by similar students in smaller districts. Fourth, increased district size, acting in concert with low student socioeconomic status, was found to be linked to higher education costs in larger districts than smaller districts with similarly impoverished students.

Based upon the support these data provided for structural deficiency theory, the continued construction and maintenance of large districts in contrast to the construction and maintenance of smaller districts is deemed to be suspect.