Arnold Kling  

Fuzzy Math

Today's Tylerisms... Geography and Economic Destiny...

The Washington Post reports,

Upon the debut of the Maryland School Assessments in 2003, Montgomery County ranked second in the state in math, with 67 percent of students passing tests in elementary and middle school. This year, the county ranks 11th.

The reporter proceeds to make a series of excuses. First, the pass rate has gone up to 82 percent in our County. It has just not gone up as rapidly as in other Maryland counties.

The county also has its share of disadvantaged students. Montgomery has the largest proportion of students with limited English proficiency, 12 percent, of any school system in Maryland. The county ranks 14th poorest in the share of students qualifying for meal subsidies by virtue of low family income, 27 percent. Both measures have risen since 2003.

Does anyone know how to get hold of this data? If so, then I have a simple suggestion for how to present it on a chart. On the X-axis, plot the percentage of students in a county who are above the FARMS line (that is the "free and reduced meals" indicator of poverty). On the Y-axis, plot the percentage of students that pass the math exam. For each county in Maryland, put a data point on the chart. Next to each data point, put the County's ranking in terms of expenditure per pupil.

Next, draw the line of best fit through the data points. Counties that fall above the line are adding relatively more value than counties below the line. If education spending matters, then Montgomery County and other high-spending schools should be above the line. It would be interesting to see whether this is in fact the case.

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COMMENTS (4 to date)
Mr. Econotarian writes:

As a former Montgomery County student, I can attest that the County population has changed dramatically.

It still has some of the best pupils and a few of the best schools in the country as it has for 30 years, but it has undergone a tremendous demographic change of recent immigrants coming into the County (and often living in those houses left behind by the white middle class as they escaped into the McMansioned exurbs of the upper-middle class).

The article mentions that 12% of Montgomery Country students have "limited English proficiency", which was not the case 20 years ago when the recent immigrant population was limited to Langley Park.

I think it is wonderful that many recent immigrants are now living in nice houses in the suburbs, sending their kids to reasonably good schools, and moving up the economic ladder. These people would be living on the edge of absolute poverty back in El Salvador, for example.

At the same time, if I was living there now and couldn't get my kids into the last remaining top public schools around Bethesda, I'd send them to private school. Peer effects are real.

KDeRosa writes:

schooldatadirect sometimes has data like this available.

I ran a few similar analyses for Pennsylvania's school districts for 2005 which provides quite a bit of data. The short answer is that educational spending matter s very little at today's levels.

post one: % passing of FARMS vs. total expenditures and % FARM students vs. total expenditures

post two: % wealthy households vs. % passing

post three: parental degree attainment vs. % passing for both FARM studenst and all students.

I still have the data in an excel file if anyone wants to run their own analysis.

kderosa writes:

Here's the chart for Pennsylvania. The data is for 2005.

For school districts falling below the regression line the average total expenditures was $11,417.

For school districts falling above the regression line the average total expenditures was $11,214.

The overperforming schools actually spent less on average. Go figure.

wintercow20 writes:


Here is my quick stab at a chart for New York State for 2005.


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