Cloaking Inequity

Written in collaboration with Dr. Jaime Portales

Guiding question for today’s post on the universal implementation of vouchers:

• Do they improve achievement?

In the largest implementation of vouchers in the world, contrasting results appear to have been found on the impact of the Chilean voucher system on student achievement among public and private schools. According to Bellei (2009), while some authors have found private school advantage (0.005 to 0.27 standard deviation) for student achievement (Gallego, 2002; Gallego, 2004; Sapelli & Vial, 2002), others have found public school advantage (0.06 to 0.26 standard deviation), Others still have found no overall statistically significant difference between them (Mizala & Romaguera, 2000; Mizala & Romaguera, 2003). Additionally, some authors have found different achievement effects depending on the period under study, or depending on the subtype of private school being considered. For example, Bravo, Contreras and Sanhueza (1999) found a private school advantage during the period 1982-1989. However, during the 1990s such advantage became statistically insignificant when controlling for socio-economic and geographical factors. The question of whether vouchers increase achievement in the midst universal implementation appear to show conflicting results.

However, before voucher proponents get too excited, it is important to note that the few studies finding achievement impacts in Chile have faced the critique that peer effects and educational stratification (see Pt II, yesterday’s post) played the most influential role in student achievement in Chile (Auguste & Valenzuela, 2004; Gauri, 1998; Hseih and Urquiola, 2004; Hseih and Urquiola, 2006; McEwan & Carnoy, 2000; Mizala & Romaguera, 2003). Overall, evidence from the Chilean voucher system suggests that student achievement, particularly the mean school achievement of a school, either public or private, largely depends on the student composition and its mean socio-economic status (SES) rather than an effect of the voucher— in essence, if you cream-skim students you can show achievement results. Changes in achievement at the school level strongly correlate with changes in student composition. Gauri (1998), examined a sample of households, studied the impact of the voucher system as applied in Santiago. He found that higher SES was positively associated with the probability of attending a school in the top third of the student achievement distribution. As a result, the Chilean case suggests between-school stratification, peer effects and creaming seem to better explain differences in achievement rather than school productivity, efficiency or market competition created by vouchers.

How about the well-publicized small-scale implementations of vouchers in the U.S. context? In preparation for this series, two weeks ago I shot an email with the voucher research to Diane Ravitch for her thoughts. She replied back:

You might add that none of the existing vouchers programs in the US has raised test scores. Not Milwaukee, not Cleveland, not DC.

She added that vouchers were especially problematic because the monies were distributed to private schools (including religious schools) without requiring accountability to the public for how those funds are spent or the achievement of the students in private schools.

In conclusion, the research on the universal implementation of vouchers in Chile shows that while voucher proponents claim that they will increase student achievement, instead, in practice on a large-scale they only show achievement results when they have magnified the inequalities (i.e. segregation and sorting mechanisms) that already exist in schools. In sum, if your goal is to improve student achievement, vouchers are not the place to look for solid educational policy. Now if you have other more insidious goals…. well, let’s chat about that tomorrow when we discuss the deconstruction of the public school system in the midst of universal vouchers.

For references, go here.