Transportation costs and student achievement

Growing up in a rural school district (I lived 20 minutes outside of a town of 1,700 people) I always wished that I didn’t have to spend a half hour on the bus every morning. I knew that I was lucky though because in middle school and high school some students spent well over an hour each way. This meant that if they were athletes they weren’t getting home from practice until 8:00 p.m. or later. I always thought this had to have a huge affect on how they did in school. After all, 2+ hours on a bus seriously cuts into the time they can spend on homework.

As part of a final project for my Educational Equality class I compiled the following statistics that relate transportation costs and student achievement. The data is limited to my home school district, Mariposa County Unified, and a relatively more urban school district, Clovis Unified.

Using publicly available data I compared the relative amounts of Per Pupil Expenditure that each district allocates for student transportation to the performance of students on the SAT and California High School Exit Exam (CAHSEE). I also compared the dropout rates in each district. The results of that research are described below and are quite interesting.

« Transportation Costs »

The total cost of transportation for each school district as a percentage of the Per Pupil Expenditure.
The total cost of transportation for each school district as a percentage of the Per Pupil Expenditure.
Transport. 2003-4 2004-5 2005-6 2006-7
Mariposa 9.32% 7.64% 7.84% 8.33%
Clovis 2.06% 1.96% 1.72% 1.77%
The first data set to compare was the total amounts spent by each district on transportation. Using the Common Core of Data I compiled statistics from 2003 through 2007. The total spent by each district was vastly different, Clovis averaged $6,687,750 per year while Mariposa only spent an average of $1,958,250 per year. 

What’s striking though is when that figure is broken down on a per student basis. When this is done Clovis spends an average of $186.02 per student while Mariposa spends $814.56.

That difference is significant and becomes even more so when compared to the total per pupil expenditure (PPE) of each district. This is what the chart at left compares. Ultimately, Mariposa Unified School District spends close to 8% of it’s PPE on transportation while Clovis Unified spends under 2%.

To put those statistics in a little bit of perspective the national average is $405 per student and states on average spend 4% of their PPE on student transportation.

That 6% difference, in total more than $500 per student, is a direct result of a more rural student population. Mariposa Unified must get these kids to school but the cost of doing could be having severe effects on textbooks and other academic resources that could be bought with $500 per student every year.

California High School Exit Exam

« CAHSEE Scores »

The next statistic to compare was how the students of each district perform on the California High School Exit Exam. This is an exam that all students in California must pass in order to graduate. They’re given multiple attempts to pass and once they pass either the math or English section they no longer have to take that portion. 

Since the test is specific to California I was not able to compare each district to national statistics but what I did was compare the performance to state-wide averages. The results are in the table to the right and are actually quite surprising.

Both districts consistently performed well above the state average in both math and English. Furthermore, the scores of each district when compared to one another are fairly similar. With the exception of Mariposa Unified’s math scores from 2004-2006 the other scores are within a few percentage points of one another.

At this point it does not seem as though there is any significant correlation between transportation costs and performance on the CAHSEE.

Mariposa 2003-4 2004-5 2005-6 2006-7
English 88% 74% 77% 86%
Math 82% 67% 66% 84%
Clovis 2003-4 2004-5 2005-6 2006-7
English 88% 81% 79% 88%
Math 87% 80% 76% 90%
State Average 2003-4 2004-5 2005-6 2006-7
English 75% 65% 61% 77%
Math 74% 63% 59% 76%

« SAT Scores & Dropout Rates »

SAT Scores vs. Percent of PPE spent on transportation 

SAT Scores 2003-4 2004-5 2005-6 2006-7
Mariposa No data 1064 1543 1535
Clovis No data 1028 1501 1488
State No data 1020 1507 1497
National 1026 1028 1518 1511
When SAT scores and dropout rates are compared between Mariposa and Clovis one can see that Mariposa students on average score more than 40 points better than Clovis students. Furthermore, Mariposa students also score significantly higher than the national and state average for SAT scores. 

In addition, with the exception of the 2003-2004 school year Mariposa Unified School District had a dropout rate that was lower than Clovis Unified.

While could easily assume that a longer ride to school everyday combined with less financial resources for a district to spend on other aspects of education would result in poorer student performance. The data though show this to frankly not be the case. Despite the higher cost of transportation Mariposa students routinely hold their own against Clovis, California, and United States counterparts in test scores and graduation rates.

« Further Information & Explanations »

Ethnicity statistics in Mariposa and Clovis Unified School Districts

Since Clovis students are not consistently outperforming their Mariposa counterparts what could be behind this? If transportation isn’t having a negative impact than what is?

My original thesis, that higher transportation costs would correlate to poorer student performance, is quite obviously not the case. If anything the correlation is between higher transportation and higher student performance on the CAHSEE and SAT.

The two graphs above provide on possible explanation. They show the average racial/ethnic backgrounds of each district from 2003 through 2007. It’s been well documented that standardized tests, and arguably the entire educational system, favor whites and disadvantage minorities. Perhaps if Clovis’ racial demographics were closer to Mariposa’s, or vice versa, the CAHSEE and SAT scores would support my initial hypothesis.

Ultimately the difference in student performance could be due to any number of factors. If any decisive conclusions are to be drawn from this short study they could only be that a greater percentage of PPE spent on transportation correlates to generally higher test scores. This is most likely a characteristic that would not translate across a broader survey.

It’s most likely the case that race, socioeconomic status, language barriers, or any variety of factors are the root cause here and that transportation costs simply have no significant impact upon the quality of education students receive.

The full statistics used in this report can be downloaded as a PDF file.