Violating the Denominator Law

December 2, 2008

Sean Corcoran, who is guest blogging for the blogger formerly known as Eduwonkette, may have to go to education research jail because he violated the Denominator Law today.  For those of you unfamiliar with the Denominator Law from my previous post on the topic (and ignorance of the law is no excuse) it is: “No one should be allowed to highlight numerators without also presenting denominators.  That is, it is often misleading to describe a big number without putting that number in perspective.”

So, Sean is all worried about private donations to public schools creating or exacerbating inequities in funding.  He references a report about California (and it had better be peer-reviewed or the blogger formerly known as Eduwonkette will throw a fit) that finds: “contributions to California school foundations rose from $123 million in 1992 to $238 million in 2001.”  He does helpfully add that $238 million only amounts to $40 per pupil.  But he doesn’t fully comply with the Denominator Law because he fails to point out that $238 million only represents .4% of the $52.2 billion in total public school revenue in California in 2001.

It’s not the average amount of private giving in California that really worries him.  What concerns him is that these donations are concentrated in wealthy areas: “Of course—as Brunner and Imazeki point out—these contributions are far from evenly distributed. Donations are strongly related to family income, and in some cases they are quite high, at more than $250 to $500 per student. (You can read about the $3.3 million education foundation in Santa Monica-Malibu Unified School District here).”

Here, your honor, is where he flagrantly breaks the Denominator Law.  He suggests that $250 to $300 per pupil, as illustrated by $3.3 million in private giving to public schools in Santa Monica, is “quite high.”  Without a denominator, it’s hard to judge how high $3.3 million in Santa Monica really is. 

Let me help.  According to the School Matters web site operated by Standard and Poor’s, Santa Monica has 12,191 students.  The private contributions Corcoran mentions amount to $271 per pupil — within his $250 to $300 range.  But total revenue for Santa Monica public schools amounted to $11,062 per pupil as of 2006.  Private contributions of $271 amount to only 2.4% of total revenue — not exactly “quite high.”

And this private giving hardly accounts for resource differences between Santa Monica and the average district in California.  According to School Matters the average district in CA had total revenue of $9,553 as of 2006, $1,509 less than in Santa Monica.  If Santa Monica received $271 in private donations compared to $40 for the average California district, the extra $231 could only account for about 15% of the extra resources Santa Monica possesses. 

If this is the worst case that folks can muster, it hardly seems like private giving is a significant contributor to resource inequities.  We only gain this appropriate perspective when we comply with the Denominator Law — so be sure to follow the law out there.

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