Small Districts — An Achievement Strategy for Iowa

Last Updated: April 01, 2006

This article appeared in the April 2006 Rural Policy Matters.

Iowa's small school districts are an "achievement blessing" that should play an important role in the state's strategy to improve education and they should be "intentionally supported" in the state's school funding system, according to a new report by the Rural School and Community Trust.

The study, More Doesn't Mean Better: Larger High Schools and More Courses Do Not Boost Student Achievement in Iowa High Schools, concludes that consolidating these small districts would not likely improve achievement, because they already perform as well as larger districts and reduce the impact of poverty on student achievement.

Several public officials and business leaders in Iowa have proposed closing smaller high schools. Some suggest requiring a minimum enrollment of 200 students while others suggest the minimum should be 400 students. The state's leading newspaper, the Des Moines Register, has endorsed consolidation as well.

The study analyzed test scores, curriculum, and demographic data from high schools below and above each of those enrollment numbers and found a consistent trend. Districts with high schools below 200 produce a slightly higher — but not statistically significant — percentage of students who scored "proficient" on math and reading tests than did larger districts. Yet these smaller districts offered fewer courses (28% fewer credits), and on average served a population that was lower in income. The median family income in these districts is more than $4,000 lower than in larger districts; the rate of eligibility for free and reduced school lunches is 9.5% higher; and, the percentage of adults with college degrees was six percentage points lower. All of these differences were statistically significant.

The analysis comparing districts with fewer than 400 high schoolers with those that were larger produced similar results except that the difference in federally subsidized meal rate was not statistically significant.

Another analysis found that reading and math proficiency levels are not influenced by the number of high school credits offered. To the extent there is any effect, it is mildly negative — the more credits offered, the lower the test scores — but the relationship is not statistically significant. (See graph in RPM 8.3, March 2006, p. 1).

The study also compared the statistical correlation between the level of poverty in a district and the test scores in that district — poverty's "power rating."  For districts with high schools under 200, poverty levels were weakly correlated to test scores, statistically explaining only 8% of the variance in achievement in both reading and math. But for larger districts, poverty levels explained 23% of the variance in reading achievement and 31% of the variance in math achievement.

When the 400-high-school-student cutoff was used, poverty's power rating in the smaller districts was 8% and 10% for reading and math, compared to a whopping 42% and 52% in the larger districts.

Depending on the test measure and the size cut off, smaller districts cut poverty's power over achievement by 65% to 81%.

Finally, the study used regression analysis to measure how reading and math proficiency varied with other factors across the entire range of school sizes, not comparing one group to another. The results were consistent with the earlier findings.

There was no statistically significant relationship between district enrollment and achievement, but there was a statistically strong relationship between poverty levels and achievement. The larger the district, the more magnified were the negative effects of poverty over student achievement, and the smaller the district, the more poverty's effects were muted.

These results suggest that increased district size in Iowa will increase poverty's power over student achievement in Iowa's schools and widen the achievement gap between wealthier and poorer students.

The complete study is available here.

Read more from the April 2006 Rural Policy Matters.