Ran across this graphic today on the rate of return states get from the money they spend on education as measured by high school graduation rates. (Click through to see the a larger version.)High school graduation is an important indicator of later financial success, with high school graduates earning $14,000 more annually than high school dropouts.
The first thing I noticed is that this is a really, really bad graphic representation of the data. What do you get from looking at this picture? Not much. There is no order, there is no representation of magnitude. Just not very effective, so I shoved the numbers from the graphic into a spreadsheet and got something a little more interesting.
You can click on the graph for a larger image - but the actual numbers are not particularly interesting. What is interesting is the randomness of the data. And why is randomness interesting? Because if spending more money on education was related to high school graduation rates you would expect the points to start in the lower left corner and move up to the upper right corner. The randomness of the points indicates the stunning lack of correlation between spending and graduation rates.
Those three points way out to the right are (from top to bottom), New Jersey, New York, and Washington, D.C. All three spend over $12,000 per child annually, but get extraordinarily different graduation results.
For those of you interested in geeky numbers, r-squared for a linear regression is 0.0373, and even for a six-degree polynomial regression (remember, there are only 51 points), the r-squared only gets to 0.2191. How low a correlation is that? If you try to correlate the first letter of the state (a pretty random value) with the graduation rate the linear r-squared is 0.0873, more than twice as high as the r-squared for dollars per student. That is a stunning lack of correlation.
Now, there are huge problems with compressing the entire education system down to two numbers. It ignores any quality factors like what the actual graduation requirements are (some states will have more demanding graduation requirements), and also what each state considers a student (are special education students included in both figures, or incarcerated youths, or students in private schools), so it's easy to quibble and get defensive on a case-by-case basis. You could also argue these figures should be weighted in importance based on population size (which these figures are not). No question that there are some apples and oranges comparisons.
What is clear in spite of those differences is that money alone does not fix the education system. Money, is probably not even the primary factor in educational success. Utah and Colorado have identical graduation rates, but Utah spends $2400 less per student. How does that happen? New York spends almost twice as much as Texas, but has a lower graduation rate. How does that happen?
Education is not a simple problem and, as this data shows, it does not have a simple answer, not even money.
Source:
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eHow
