Forty-one Connecticut school districts are more than twice as efficient as Hartford schools.

Forty-one Connecticut school districts can educate two high school graduates for less than the cost of one Hartford graduate, according to Department of Education data.

That means nearly half of the 111 districts reviewed are twice as efficient as Hartford public schools.

Hartford schools spent $288,490 to get one student from kindergarten to high school graduation. The average cost of a diploma in 2012 was $150,943 over 13 years.

New Haven, New Britain, Windham and New London are the other most expensive school districts.

The Tolland, Wolcott, Suffield, Madison and New Fairfield school districts are the most efficient in the state. They accomplished this by combining relatively low total costs per student and high graduation rates.

Madison School District, in addition to being the fourth most efficient district, also ranked in the top ten districts with highest rate of CAPT proficiency.

Madison is the only district to rank in the top ten for both efficiency and CAPT proficiency.

Shelton and Regional School District 14 were the only districts to decrease adjusted total costs, both by more than $6,000.

In DRG A, Darien, New Canaan and Weston school districts all boasted the state’s top average CAPT proficiency rate of 98.5 percent. However, Darien accomplished this rate while spending $13,000 less than both schools and the second lowest amount in the peer group.

DRG B had the highest concentration of low-cost districts. Thirteen of 18 school districts are among the most-efficient third of districts. All 18 schools had at least 91 percent CAPT proficiency.

Greenwich was by far the most expensive district in the peer group, outspending the next district by more than $43,000, yet they had the fourth-lowest CAPT proficiency in the DRG.

Colchester was the lowest-cost district in its peer group, but had average proficiency rates compared to the group.

In DRG G, a high concentration of costly schools means that the average adjusted ranking is 32.6, below the threshold for the most expensive third in the state.

The worst performing group, however, was DRG I, which contains the state’s five most expensive districts. These high costs fail to correspond with academic success. The group contains six of the 10 lowest average proficiency percentages and has an average graduation rate of only 64 percent.

Raising Hale has done similar rankings in 2010 and 2011, but the Department of Education changed the way it calculates graduation rates two years ago. Since there is a two-year lag in the data, this change is reflected for the first time this year.

Under the new method of calculating graduation rates – by cohort, or incoming freshman class – many graduation rates are lower than under the old method.

For example, in 2011 only 10 schools were more than twice as efficient as Hartford schools. Under the new ranking, 41 schools are more efficient.

Hartford’s per-diploma cost increased by almost $50,000 because of the change. The average cost for a diploma statewide increased more than $10,000.

2012 Data

Sorted by Rank | DRG | Alphabetical

Highest-cost districts
1. Hartford School District $288,489.97
2. New Haven School District $263,179.20
3. New Britain School District $244,847.40
4. Windham School District $244,025.48
5. New London School District $242,511.74
Average cost: $150,943.41
Lowest-cost districts
107. New Fairfield School District $128,492.99
108. Madison School District $128,321.13
109. Suffield School District 128,019.52
110. Wolcott School District $125,278.02
111. Tolland School District $123,006.33

Methodology:

To calculate the cost per graduate, the Yankee Institute took data from the Connecticut Department of Education for average annual expenditures per student going back 13 years, representing K-12. After totaling the cost, it was divided by the graduation rate to come up with the lifetime cost per graduate. The 13th year is the 2009-2010 school year, and data is not adjusted for inflation, so the real cost of 2012 graduates is higher than calculated. Communities with high annual costs, more drop outs and lower graduation rates end up with the more expensive graduates. Some regional school districts, districts with less than 13 years of data, charter schools and other non-traditional schools were left out of the calculations to keep the data consistent for the greatest number of schools.

Also, the calculations do not include costs for school construction or teacher pensions, both of which are paid for by the state.

The data for 2012 represents several new measurement techniques which differ slightly from previous reports.

In the past, the graduation rate was a measurement of the percentage of students who entered their senior year in a particular school district and then graduated from that district in the spring. The 2012 data reflects a change to a new cohort graduation system.  According to the Connecticut Department of Education, this measurement reflects the percentage of students who enter a district as freshmen and then graduate four years later.

This change has led to some artificially high changes in graduation rates and rankings.  School districts disadvantaged by this new system are those that have many more students leave the district (due to transfer or drop-out rates) during all four years of high school. They include: Ansonia, Bristol, Coventry, Derby, East Haven, Groton, Manchester, New Milford, Shelton, Watertown and West Haven school districts.

A second deviation from previous measurements is in the measure of academic achievement. Last year, school performance was measured using the Global Report Card, which compared the average student in each district’s score on standardized tests to all other students in Connecticut.  However, more recent Global Report Card data is not available. Instead, the 2012 data uses the percentage of a school district’s students deemed at or above proficient in the standardized CAPT reading and math tests. The two percentages for CAPT Reading and CAPT Math were averaged to find an average, which was used to rank the districts statewide.  A lower ranking means higher scores, while higher rankings correspond to lower average scores.

Correction: A data entry error caused the graduation rates for New London, New Milford and Newington to be reported incorrectly. The relevant data for the three districts has been corrected, as has the ranking for all districts. Bridgeport was incorrectly identified as the fifth most expensive district. It ranks sixth. New London moves up to fifth.

Yankee Institute intern Zack Albert contributed to this article. He is a junior studying political science and economics at Fairfield University. He lives in Southington.