More Investments Does NOT Equal Better Test Scores
Counter intuitively, more investments by the school per pupil does not equal better test scores by the student body.
Although schools with lower percentiles of English Learners tend to do better on exams, there is a very clear threshhold to the extent that this holds true.
This is particularly made clear by analyzing the average SAT scores of Texas schools:
Schools with EL% of 0-30% tend to score better on the SAT than schools with student bodies which consist of 30.1-65% of English Learners. However, schools with student bodies of 65%< of English Learners ALSO score on the SAT better than schools with 30.1-65% of English Learners.
In fact, schools with greater than 65% of English Learners score better than almost every other EL% range, except for the 0-5% and the 10.1-15% EL% range, despite having the lowest Operating Revenue/Pupil margins:
| %EL Range | Avg % of Students in %EL Range With All Subject Test Scores Meeting Grade Level Standard or Above | Avg SAT Test Score | Avg ACT Test Score |
| 0-5% | 48.86 | 1062.89 | 20.51 |
| 5.1-10% | 45.40 | 1047.10 | 20.27 |
| 10.1-15% | 45.36 | 1053.50 | 20.37 |
| 15.1-20% | 42.59 | 1008.69 | 19.60 |
| 20.1%-25% | 39.41 | 1003.50 | 18.98 |
| 25.1-30% | 42.24 | 1029.88 | 19.89 |
| 30.1-35% | 42.30 | 987.29 | 19.51 |
| 35.1-40% | 40.93 | 983.00 | 19.15 |
| 40.1-45% | 38.35 | 953.36 | 18.39 |
| 45.1-50% | 37.00 | 943.00 | 17.83 |
| 50.1-55% | 39.57 | 944.60 | 15.60 |
| 55.1-60% | 38.25 | 893.75 | 15.83 |
| 60.1-65% | 42.17 | 985.50 | 17.80 |
| 65%< | 42.88 | 1050.50 | 17.85 |
Some possible explanations for the inconsistency between funding and Test scores:
1. The majority of students – EL or non-EL – fall in the 0-35% range, meaning the school districts that they attend tend to be bigger in size. Larger school districts have an exponentially higher number of non-academic school-related expenses, such as school security, administrative expenses, teacher salaries, extracurricular activities, facility maintanance, school sports, and various forms of counseling and student-support.
It is therefore likely that these school districts – although they have more money on balance – spend less on each individual student's academic development.
2. It is possible that as a school district sees an increase in English Learners, there becomes an exodus of non-English Learners from that school district as parents decide to switch the school districts that their children attend. This would also explain why there isn't a consistent basis for the test scores of students in each percentile range – non-EL students will tend to do better on early age academic assessments, so a large exit of non-EL students would create an imbalance in the individual districts' test performance.
Historically, Texas schools have not been very effective in creating curriculums specifically tailored to bilingual education – students whose parents have requested that their children be placed in bilingual education programs have not been properly accomodated due to a lack of existing infrastructre for ESL programs. For school districts that did not have an already existing infrastructure for ESL programs, students have historically had to be placed into other programs that were already established, such as Special Education. For this reason, it's possible that many parents choose to enroll their kids into schools that focus on STEM and Liberal-Arts focused schools rather than those which now do have more organized bilingual and ESL programs. It could also be the case that as parents witness their children's schools become more gentrified, their personal prejudice compels them to send their children to other public schools or to private schools with fewer percentages of English Learners. For parents who have children in their early years of education, this would explain why there are some inconsistencies in test scores, as younger children who are non-English Learners tend to do better on standardized exams – removing younger non-EL children from schools could lead to lower average test scores for that school district.
3. Schools with lower populations of English Learners do not need to specifically tailor their academic curriculum to non-EL students to the same degree that school districts with higher percentiles of English Learners do. School districts with higher numbers of English Learners have to tailor their teaching methods to be more direct, as to accomodate English Learning students, particularly in the early years of primary schooling. This level of "explicit teaching" would mean that English Learners in these districts would be better prepared specifically for the concepts assessed in the STAAR, SAT, or the ACT relative to their peers who attend schools with fewer English Learners and a more comprehensive education curriculum.