California Vaccination Exemptions by Type of School

by Kieran Healy on February 5, 2015

Update, Feb. 5th: Figure and Table updated to identify Catholic Private schools. And again later the same day, finding more Catholic schools.

I took another look at the vaccination exemption data I discussed the other day. This time I was interested in getting a closer look at the range of variation between different sorts of schools. My goal was to extract a bit more information about the different sorts of elementary schools in the state, just using the data from the Health Department spreadsheet. As we saw before, the smaller the unit of observation the more variability we are likely to uncover. So, looking at the rate of Personal Belief Exemptions (PBEs) in public vs private schools shows less variation than looking at the rates across counties, which in turn show less variation than what we observe at the district and school level. At the same time, the larger the number of observations within any particular category, the more variability there is likely to be as well. There are far more public schools than any other sort of school in California, so even if most public schools have very low rates of PBEs, the fact that there are thousands of them makes some outliers more likely.

To get a more fine-grained sense of the different sorts of schools there are, I used their names as a guide. How many private schools have the word “Christ” or “Christian” in their names, for example? How many have “Waldorf” or “Montessori”? This is an imperfect measure because it’s not guaranteed that, say, a private Christian academy will have the words “Christ” or “Christian” in its name. But it’s imperfect in a generally conservative direction—though not uniformly, as if you don’t search carefully you might mistake Christa McAuliffe Elementary, a public school, for a private Christian school. So you take care not to write regular expressions that aren’t too greedy, and double check against their public/private status, which is also given in the CDPH data. With this in mind we can produce a table of different types of schools ordered by mean PBE rate.

Type Mean PBE Median PBE Max PBE Min PBE N Schools N Students
Private Waldorf 47.49 44.19 84.21 20 16 513
Public Montessori 17.08 12.24 54.55 5.97 11 706
Charter Montessori 14.28 10.26 31.67 4.35 5 227
Charter 10.76 3.03 70.37 0 314 19,863
Private Christian 6.74 3.70 92.86 0 333 8,763
Private Non-Specific 5.89 0 86.96 0 596 16,795
Private Montessori 4.64 0 35.71 0 98 2,101
Private Jewish or Islamic 2.59 0 14.29 0 8 237
Public 2.33 0.81 75 0 5314 472,802
Private Catholic 1.80 0 27.78 0 333 8,855
Private Christian Montessori 1.25 0 5 0 4 78

Apologies for the rather ugly table. The data show right away that, in addition to the broad differences between types, there’s both a a lot of variability in almost all the categories of school. Some of the categories have very few schools, but I’ve kept them for the sake of detail. The median charter, Christian, and private Montessori schools have relatively low PBE rates. Catholic schools have lower PBE rates than the public schools. Charter schools and charter Montessoris have much higher median PBEs—over ten percent. The same goes for an interesting group of public Montessoris (I didn’t know that California had public Montessoris before looking at this data.) The highest median PBE rate by far is in Waldorf schools, at 44 percent. There are just sixteen of these schools in the whole of California.

Here’s a figure that tries to capture the heterogeneity of PBE rates across types of school.

California Kindergarten PBE Rates by Type of School, 2014-2015

California Kindergarten PBE Rates by Type of School, 2014-15.

(Click for full size; PDF available.)

Each circle is a school. I’ve scaled them a little to reflect variation in the number of pupils enrolled. As before, this is kindergrarten enrollments not overall school size. Within each type of school, the vertical axis doesn’t mean anything: the points are just jittered a little to make them more easily visible. A note at the right hand side reminds you how many schools and how many students are represented in each row.

As I say, Montessori schools are interesting. Their patterns cut against the expected associations: there are private Montessoris with relatively high PBEs, but most of them are down around zero. The same goes for the small number of Christian Montessoris, which have near-zero PBE rates. Meanwhile charter Montessoris have high PBE rates, as do the public Montessoris. Perhaps unsurprisingly, three of the high-scoring public Montessoris are in Sacramento county, and two more are in nearby El Dorado and Nevada counties. Two of the Waldorf schools are also in Sacramento and one is in El Dorado county. Charter schools are also clearly overrepresented in the high-PBE group, and in contrast to, say, high-PBE private schools, many of them are relatively large. (Though some of the very largest are actually service providers to home-schoolers.) Meanwhile in the public schools, the large majority of students are concentrated in schools with low PBE rates. But because there are more than five thousand public schools there are plenty of high-scoring examples as well. Exploring the geographical distribution of these schools would be a natural next step to take with the data here. Even so, as we’ve seen, you can get a lot out of just the data in the basic spreadsheet.



rootlesscosmo 02.05.15 at 2:33 am

Does the category “Private Christian” include Catholic parochial schools? Is there a way to disaggregate them from private Christian schools operated by Protestant denominations, and if so, is there a difference in vaccination rates?


Steve Sailer 02.05.15 at 2:39 am

Back in the 1990s, Waldorf schools were popular among other mothers my wife called “brown ricers” — they tended to be white, well-educated, liberal, environmentalist, feminist in theory but not in practice, and worried about vaccines. Nice people.


marcel 02.05.15 at 3:14 am

Would searching on “Saint”/”St.” in the name increase the number of Christian (perhaps parochial) schools identified.


js. 02.05.15 at 4:13 am

Charter schools and charter Montessoris, however, have much higher median PBEs—over ten percent.

Mean PBEs, perhaps? Because unless I’m reading the table wrong, the median PBE for charter schools seems to be 3.03.

(Which in fact the previous sentence—“The median charter, Christian, and private Montessori schools have relatively low PBE rates. “—seems to say.)


rootlesscosmo 02.05.15 at 4:24 am

Probably. But you’d miss an unknown proportion–Mercy, Sacred Heart, Presentation (major Catholic schools in San Francisco) etc. There’s probably some diocesan list though I don’t know how to access it.


RoyL 02.05.15 at 8:13 am

@3, I agree with Marcel. While I live in the PNW, and no longer in California, most of the really reactionary christians I know send there kids to schools with St in the title and not Christian, and these are Calvinists and not Catholic. Considering the church’s position on vaccination, I would suspect Catholic schools would have very low rates.


RoyL 02.05.15 at 8:15 am

I mean that Catholic schools would have low rates of exemption from vaccination.


Kieran Healy 02.05.15 at 11:45 am

Hi all, I woke up this morning with the same thought and pulled out the Catholic schools. Post updated.


Kieran Healy 02.05.15 at 11:46 am

By the way, the highest-PBE Catholic school is a homeschool support service, a bit like some of the very high-scoring Charters schools.


Moby Hick 02.05.15 at 2:12 pm

Are there really only 95 Catholic schools in the state? There’s probably that many within a 60 minute drive from here, but I don’t know what they get up to out on the west coast.


Kieran 02.05.15 at 2:38 pm

I’m almost certainly undercounting. I may get another chance later today to have another go at identifying other ones. Right now I’m minimizing false positives.


Moby Hick 02.05.15 at 2:42 pm

I’m sure you did your best, but last week was Catholic Schools Week.


Kieran Healy 02.05.15 at 4:10 pm

OK, found a bunch more (ST. rather than SAINT, all Private, and also learned that Lutheran schools have Saints’ names.) Trend is in the same direction—Catholic Private Schools have much lower exemption rates than even Public schools.


Moby Hick 02.05.15 at 4:12 pm

I didn’t mean to make you do work. Sorry.


oldster 02.05.15 at 5:03 pm

“So you take care not to write regular expressions that aren’t too greedy, and double check” for double negations….


Zamfir 02.05.15 at 6:30 pm

most of the really reactionary christians I know send there kids to schools with St in the title and not Christian, and these are Calvinists and not Catholic.
I am surprised to learn this. Here in the Netherlands, the hardcore Calvinists don’t like vaccinations, but they truly hate saints. Polytheism in disguise.


mpowell 02.05.15 at 6:54 pm

Isn’t Waldorf the homeopathy of educational methods? So this result would exactly make sense in that case?

Since the concerns with herd immunity are related to immunization rate thresholds, the higher count PBE schools are more important than the mean (unless the mean is above the threshold!). And given the large absolute number of public schools with high PBE rates on this list, I’d say this is a situation where the simple legal remedy will be quite effective. I doubt the vast majority of those public PBEs are willing to pony up for private school to defend their PBE.


Harold 02.05.15 at 7:36 pm

The Spiritualists of the late nineteenth and early twentieth c.s opposed vaccination. This was true even of Alfred Russel Wallace, who was right about almost everything else. He argued that lower disease rates were due more to improved sanitation than to the discovery of vaccines. Medical science in those days did do a lot of harm. But rest, cleanliness, and fresh air observably did a lot of good. The immune system had not yet been discovered and people were afraid of injecting disease elements into their bodies.

Lots of Waldorf parents are against vaccination, and were so independently of Waldorf. Home schoolers tend to be against it. It was the hippie zeitgeist. Perhaps it was inherited from Theosophy, more likely it was a result of a combination of not having personally had experience with infectious disease (ironically due to the discovery of anti-biotics and vaccinations) and a generally anti-authoritarian attitudes.

I sent my daughter to a Waldorf school and like most parents there had my children vaccinated. I also had an anti-vaxxer friend who took her children to a pediatrician (MD) in a Waldorf community in Spring Valley NY. This gentleman persuaded her to get her children immunized for everything I think except whooping cough maybe, just to satisfy her desire to be a non-conformist. He also gave her some homeopathic “medicines.”

Whooping cough really is endemic in Waldorf communities. As the parent of a school age child, I think I even may have contracted a mild (though awful) case myself, despite having been vaccinated in childhood. I think they now give a booster to adults.


Nickobrats 02.05.15 at 8:54 pm

Great looking chart – Silly question; what program did you use to make it?


Main Street Muse 02.06.15 at 1:21 am

Do a lot of Waldorf children die from the diseases they’re not vaccinated against?


Harold 02.06.15 at 5:37 am

Main Street Muse @20 I don’t think Waldorf schools take a position on vaccination. I have never heard of any deaths. I have heard gossip about whooping cough.

I did have an argument once about vaccination for measles with a parent of a Waldorf nursery school child. I was not able to convince her. (I don’t think they kept their child in Waldorf.) Lots and lots of parents, who do not send their kids to Waldorf schools are anti-vaxers. It is or was a counter-cultural fad.

As I said, the pediatrician at the Rudolf Steiner community in Spring Valley (he was a German-born MD) did do vaccinations for his patients. Not only that, he argued with the non-vaxxer parents and succeeded in persuading them to have it done.

Our own pediatrician (who was not in any way affiliated with Waldorf) and who on the staff of St. Lukes Roosevelt, gave us a choice, he said, the side effects are terrible, but very rare. We chose to vaccinate.

Our daughter graduated from a Waldorf school, was accepted (early admission) to a good university, and graduated with a major in ancient near eastern studies and classical languages. Several of her Waldorf high school classmates (class of 35 students or so) are now medical doctors. One is a veterinarian. One is a professional lacrosse player. As far as I know, all of them believe in vaccination. So I would say Waldorf education produces results (when the method is followed, as is the case with many other methods).

On the other hand, the Waldorf schools are all independently run and some may have different policies.


Tom h. 02.06.15 at 3:53 pm

Here is a list of Waldorf inspired public charter schools.


Harold 02.06.15 at 9:08 pm

There are many Waldorf schools that are not Charter schools.


John Emerson 02.07.15 at 3:29 am

The Catholic belief in authority might make them less willing to accept PBEs, especially because the belief would not be orthodox Catholic belief.

The state with the fewest PBEs is Mississippi, also authoritarian.

I draw no conclusions from this, though I do believe that some people need to think inside the box more, and that some Question Authority-arians are nuts.


Harold 02.07.15 at 1:49 pm

An explanation of why Montessori schools do not have a high rate of vaccination exemption is that they are based on Catholic philosophy, which is not countercultural or anti-establishment.

I agree that some Question Authority-arians are nuts, and chances are they are following some other Authority, such as that of the vitamin supplement industry. However, you also have to wonder how Authority lost the trust of so many people.


Jim V 02.09.15 at 1:47 am

All three of my children went to Catholic school, not because of any deep religious involvement but because my wife worked in the public school sector. Incredibly diversified ethnically and apparently a good experience all around. To the best of my knowledge, most, if not all families made sure their kids were vaccinated. We spent 15 years with other families raising children, if there was anti-vaccine sentiment, I think I would have heard about it.

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