Tuesday, July 15, 2014

Teachers And Education Reform, On A Need To Know Basis Posted by Matthew Di Carlo

A couple of weeks ago, the website Vox.com published an article entitled, “11 facts about U.S. teachers and schools that put the education reform debate in context.” The article, in the wake of the Vergara decision, is supposed to provide readers with the “basic facts” about the current education reform environment, with a particular emphasis on teachers. Most of the 11 facts are based on descriptive statistics.
Vox advertises itself as a source of accessible, essential, summary information — what you “need to know” — for people interested in a topic but not necessarily well-versed in it. Right off the bat, let me say that this is an extraordinarily difficult task, and in constructing lists such as this one, there’s no way to please everyone (I’ve read a couple of Vox’s education articles and they were okay).
That said, someone sent me this particular list, and it’s pretty good overall, especially since it does not reflect overt advocacy for given policy positions, as so many of these types of lists do. But I was compelled to comment on it. I want to say that I did this to make some lofty point about the strengths and weaknesses of data and statistics packaged for consumption by the general public. It would, however, be more accurate to say that I started doing it and just couldn’t stop. In any case, here’s a little supplemental discussion of each of the 11 items:
1.     Teachers earn a bit more than the average American. This fact presents a simple comparison, using BLS data, of median elementary and secondary school (public and private) teacher earnings with those of the median U.S. household. There are a few issues here (most are mentioned in the article). First, I have no idea why, but this is comparing an occupation-level figure (for teachers) with a household-level figure. Second, it is comparing teachers’ earnings with those of all workers (households), rather than workers with similar education and experience. Third, the comparison omits non-salary compensation (i.e., benefits), which are an important part of this picture. These caveats, the first two in particular, make for a less-than-meaningful contrast. Overall, this illustrates how seemingly basic comparisons, such as earnings between occupations, can be painfully complicated - even using more sophisticated methods, it depends on how compensation is measured and the choice of comparison groups. It also bears mentioning that, for some advocates, the big issue in education today is as much about how teachers are paid as about how much they are paid.
2.     Americans say teaching is a prestigious career. This item uses polling data to compare how people perceive the prestige of the teaching profession (quite highly) with that of a selection of other occupations. I think this is a good one, especially given all the heated rhetoric (from both sides, ironically) about “reprofessionalizing” or “deprofessionalizing” teaching, or about how young people avoid teaching due to its reputation. In reality, most people hold the profession in high regard. Also, as a side note, if you go to theoriginal report from Harris Interactive (the data source link in the article seems to be incorrect), it’s very interesting to see that the proportion of respondents saying teaching has “very great prestige” almost doubled between 1977 and 2009 (from 29 to 51 percent).
3.     Elite students tend to avoid teaching. Using data from a widely-cited McKinsey report, this one points out that incoming teachers’ SAT/ACT scores are lower than those of graduates who pursue other careers (in terms of the common “top/bottom third” figures, which we discuss here), and that this is not the case in a few other nations that receive attention for their high test scores. On the substance, as is discussed in the post linked above, SAT/ACT scores are among the only measurable pre-service characteristics that has a record of being associated with value-added scores once graduates start teaching (which is, of course, just one measure of effectiveness), but the association is not particularly strong. Overall, predicting who will be a good teacher before they enter the classroom remains remarkably elusive, and I think that generalization, while not a “fact” in the same sense as are descriptive statistics, is probably the most important thing to keep in mind when talking about attracting the “best candidates” to the profession.
4.     Absolute teacher salaries are high. Here, based on OECD data, we see that teacher salaries throughout their careers (the graph shows salaries after 10 years on the job) are a bit lower than they are in other OECD nations. As was the case with the U.S. figures, this comparison fails to account for differences in the cost of health and pension benefits, but that’s just a quibble (and tough to compare between nations). Note, though, that the evidence that salaries have an impact on the quality of candidates or whether they remain is not entirely consistent – it varies by context and other factors (see the papers cited in this post).
5.     Relative teacher salaries are low in the U.S. This compares teacher salaries to OECD nations as a proportion of college graduates’ salaries. I like the idea of at least trying to compare teachers with similarly-educated workers (which was not done in #1), although I would reiterate that the role of salary in who pursues and remains in teaching, at least in the U.S., is not as clear as one might think. 
6.     Some teachers are much more effective than others. The flagship piece of evidence here is a graph from a published article by economist Eric Hanushek, one that is based on a rough, illustrative calculation that expresses teacher effects in terms of classroom-level lifetime earnings (thus making for huge numbers as one moves toward the right of the [unlabeled] class size horizontal axis). In my view, there are better ways to express this important finding about the variation in teacher effects that also would have been accessible to people not accustomed to thinking in terms of standard deviations. That said, this is probably the most important point among the 11 presented in this article, if for no other reason than the sheer magnitude of its impact on the debate and policymaking.
7.     Class sizes have fallen substantially. This item presents declining student/teachers ratios alongside the number of teachers in the U.S. since 1960, using NCES data. These ratios are a crude measure of class size (more teachers per student doesn’t translate directly into smaller classes, particularly given the sharp increase in special education teachers that occurred within this time period). The size and scope of the trend, however, are sufficient to make the point that class sizes have decreased over the long-term, even if the decline may be more moderate than is suggested by the graph. This is an important point in the context of contemporary education reform in the U.S. (but it might have been helpful to discuss briefly some of the research on this topic).
8.     The teaching workforce is disproportionately unionized. Here, BLS data are used to show that unionization rates for the occupational group “Education, library and training workers” are higher than the rates for local government, public sector workers , and private sector workers. As the article notes, the BLS website does not offer teacher-specific unionization rates, but there are reputable resources that produce such estimates (using BLS data). They show that between 45-55 percent of teachers are union members and/or covered by a contract. Note, however, that these figures, like the category-wide statistic presented in the article (Education, library and training workers), include both public and private schools teachers (and thus understate unionization rates, since the latter group is largely non-union). Still, all of these sources make roughly the same point– teachers are more heavily unionized than most other U.S. occupations, particularly those in the private sector. Of course, the big issue in education is not really whether teachers are unionized, but rather whether unions, and collective bargaining in particular, have a large impact on school performance. This issue is (predictably) complicated and largely unresolved
9.     Per pupil funding varies widely. A simple color-coded U.S. map is used to illustrate funding disparities between states. As was the case with the class size, I think this (i.e., funding) is an important general topic, even if raw per pupil figures, though easy to understand, aren’t necessarily the best measure in this context, given that student characteristics vary quite widely between states, and they play a major role in determining funding at the federal, state and local levels. Perhaps including a funding fairness or similar measure, or at least mentioning them, would have been better. Nevertheless, funding does matter, and the article’s point — that it varies between states — is certainly important.
10.   Dropout rates are falling. The chart in the article shows dropout rates falling since 1970 for different student subgroups. Again, this is a tough outcome to measure nationally. More importantly, it seems redundant with #11.

11.   Students are broadly doing better. This is a simple graph of trends in Long-Term NAEP scale scores by age and subject (math/reading) since 1971. The scores are clearly increasing. This is an important point to make in any list of this type, and these are good data with which to make it. The only thing I would add — and it’s no less important — is that the degree to which these trends are due to improvements in schooling, to say nothing of teacher quality, rather than the dozens of other factors that affect testing performance (including change in the sample of test takers), is unclear. No question, though – this one is “need to know.”

To read more, click on the following link:
http://shankerblog.org/?p=10024

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