Tuesday, August 28, 2012

The real effect of teachers union contracts

An oldie but goodie from the Shanker blog, repub at the Answer Sheet, Oct. 2010

By Valerie Strauss
Teachers unions are a big target today of some school reformers who view these organizations as the biggest obstacle to improving student achievement. The film "Waiting for Superman" certainly did. So why are states without binding teacher contracts among the lowest-performing in the nation? Matthew Di Carlo, senior fellow at the non-profit Albert Shanker Institute, located in Washington, D.C., looks at this issue. A version of this post originally appeared on the institute’s blog. A follow-up to this post presented a supplemental analysis of the data.

By Matthew Di Carlo
For years, some people have been determined to blame teachers’ unions for all that ails public education in America. This issue has been around a long time (see here and here), but, given the tenor of the current debate, it seems to bear rehashing. According to this view, teachers unions negatively affect student achievement primarily through the mechanism of the collective bargaining agreement, or contract. These contracts are thought to include “harmful” provisions, such as seniority-based layoffs and unified salary schedules that give raises based on experience and education rather than performance.
But a fairly large proportion of public school teachers are not covered under legally binding contracts. In fact, there are some 10 states in which there are virtually no legally binding K-12 teacher contracts at all (there are none in AL, AZ, GA, MS, NC, SC, TX, and VA; there is only one district with a contract in LA, and two in AR). Districts in a few of these states have entered into what are called “meet and confer” agreements about salary, benefits, and other working conditions, but administrators have the right to break these agreements at will. For all intents and purposes, these states are largely free of many of the alleged “negative union effects.”
Here’s a simple proposition: If teacher union contracts are the main problem, then we should expect to see at least somewhat higher achievement outcomes in the 10 states where there are basically no binding contracts.
So, let’s take a quick look at how states with no contracts compare with the states that have them.
In states where there are binding contracts, there is some variation in coverage (the percentage of teachers covered under contracts). In most of them (34, plus Washington D.C.), districts are required to bargain with unionized teachers, and coverage in these states is very high. There are a few other states in which contracts are binding once they’re finished, but districts are not required to bargain (Louisiana also technically falls into this category, but since Katrina, there is only one contract in force). The results for these states are virtually identical to those for the bargaining states.
In the table below, using data from the 2009 National Assessment of Educational Progress (NAEP), I present average scale scores for states that currently have binding teacher contracts and those that don’t. The averages are weighted by grade-level enrollment, and they include only public non-charter schools (since most charters in all states have no contracts).

Average 2009 NAEP Score By State Teacher Contract Laws
States with binding teacher contracts
4th grade: Math 240.0 Reading 220.7
8th grade: Math 282.1 Reading 263.7
States without binding teacher contracts
4th grade: Math 237.7 Reading 217.5
8th grade: Math 281.2 Reading 259.5
As the table shows, the states in which there are no teachers covered under binding agreements score lower than the states that have them. Moreover, even though they appear small, all but one of these (8th grade math) are rather large differences.
To give an idea of the size, I ranked each state (plus Washington D.C.) by order of its performance —its average score on each of the four NAEP exams – and then averaged the four ranks. The table below presents the average rank for the non-contract states.

Average Rank Across 4 NAEP Tests

Next to each state is its average rank
Virginia....... 16.6
Texas......... 27.3
N. Carolina.. 27.5
S. Carolina...38.9

Out of these 10 states, only one (Virginia) has an average rank above the median, while four are in the bottom 10, and seven are in the bottom 15. These data make it very clear that states without binding teacher contracts are not doing better, and the majority are actually among the lowest performers in the nation.
In contrast, nine of the 10 states with the highest average ranks are high coverage states, including Massachusetts, which has the highest average score on all four tests.
If anything, it seems that the presence of teacher contracts in a state has a positive effect on achievement.
Now, some may object to this conclusion. They might argue that I can’t possibly say that teacher contracts alone caused the higher scores in these states. They might say that there are dozens of other observed and unobserved factors that influence achievement, such as state laws, lack of resources, income, parents’ education, and curriculum, and that these factors are responsible for the lower scores in the 10 non-contract states.
My response: Exactly.

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