Swedish Study: Voucher Schools Improve Everyone’s Achievement

Anders Böhlmark Mikael Lindahl

What will free schools mean for the quality of education — in the new schools, and in the old ones they compete with? In Sweden, they don’t have to guess. They have almost 400 free schools, and data from millions of pupils. The latest study has just been published, and has strong results that I thought might interest CoffeeHousers (you can read the whole paper here). It makes the case for Michael Gove to put the bellows under the free school movement by following Sweden and let them be run like expanding companies (that is to say, make a profit). It finds that:

  1. Growth of free schools has led to better high school grades & university participation, even accounting for other factors such as grade inflation.
  2. Crucially, state school pupils seem to benefit about as much as independent school ones. When ‘bog standard comprehensive’ face new tougher competition, they shape up. They know they’ll lose pupils if they don’t. As the researchers put it: ‘these positive effects are primarily due to spill-over or competition effects and not that independent-school students gain significantly more than public school students.’
  3. Free schools have produced better results on the same budget. Their success cannot be put down to cash. Or, as they say, ‘We are also able to show that a higher share of independent-school students in the municipality has not generated increased school expenditures.’
  4. That the ‘free school effect’ is at its clearest now because we now have a decade’s worth of development and expansion.

Via Competition in Schools by Chris Cook.

Fraser Nelson, editor of the Spectator, has written up a paper on Swedish school reforms, which you can download here. I thought it was worth using to quickly flag up two important statistical public policy points.
The context to this is that Sweden has, since the early 1990s, allowed private (including for-profit) institutions to enter the school system – and parallels are often drawn between it and the ongoing reforms of England’s school system. This paper, as Fraser rightly says, comes to the view that increasing the volume of private schools in an area is associated with improved results. Mikael Lindahl and Anders Böhlmark say:

If we transform our estimates to standard deviation (S.D.) units (using the variation across all individuals) we find that a 10 percentage point increase in the share of independent-school students has resulted in 0.07 S.D. higher average educational achievement at the end of compulsory school.

This is a statistically significant finding. That is to say that it is not likely to be the result of random happenstance. But it is important to look beyond the significance to effect size – so it’s not luck, but is it a big effect? That is where the Swedish paper makes me suck my teeth. It suggests that if you were to introduce a ten percentage point increase in private provision, you would only get a 0.07 standard deviation increase. I cannot help thinking that’s a pretty meagre return on such a massive disruption in the system.


Read the paper here (500K PDF).