Early-childhood intervention has become a popular policy tool in recent years for improving outcomes over the long term. Investment in the early years is regarded as offering a higher return, as benefits accrue over time, just as disadvantage gets worse with neglect.  

Yet there is generally less consideration of the flipside of the argument: if successful early-childhood interventions have long-lasting positive effects, we should also expect failed ones to have long-lasting negative effects. 

Accordingly, early-childhood interventions would be expected to have higher risks attached than interventions carried out later. It is thus all the more important that policymakers opt for interventions supported by evidence rather than ideology and intuition.

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In a new paper for the American Economic Journal, which we feature in this month’s Centre for Education Economics Monthly Research Digest, Michael Baker, Jonathan Gruber and Kevin Milligan evaluate the longer-term effects of an early intervention that has become increasingly popular in the past decades: universal childcare. 

In 1997, policymakers in Quebec, Canada, introduced regulated childcare places to all children up to age 4 at a subsidised price of $5 per day. Provision was extended through non-profit childcare centres and regulated home-based care providers. 

Voluntary full-time kindergarten was expanded, and after-primary school care subsidised. 

Qualification requirements were introduced for all caregivers. The quality of the programme was deemed comparable to that provided in other developed countries.

Negative impact

Yet research found striking negative short-term effects on children’s non-cognitive performance, and that these persisted as the programme matured. Some research also found immediate negative effects on cognitive development. 

In this paper, Baker and colleagues investigate whether these negative effects have implications for outcomes later in life, including cognitive performance, criminal behaviour, health, and life satisfaction. 

By analysing whether the reform affected differences in outcomes between children in Quebec and in other provinces, and by showing that there are no similar pre-reform trends in those differences, the authors are able to separate causation from correlation.

Early intervention

The authors first replicated the findings of the prior research mentioned above, showing that the reform had strong positive effects on take-up of childcare but considerably increased children’s anxiety and aggression in the immediate term. They also found negative effects on cognitive performance.

They then found that these effects persist and, in terms of anxiety, increase substantially when children affected by the reform are between 5 and 9. At this age, there is also a negative impact on hyperactivity. 

In other words, there is little evidence that the negative effects fade out as children get older.

Long-term damage?

Indeed, the programme also had clear negative effects on outcomes in adolescence: it decreased self-assessed health and life satisfaction as well as increased crime rates as the children reached adulthood. 

The findings on longer-term cognitive outcomes are mixed and there is no impact on self-assessed mental health. 

Best evidence

Overall, the paper highlights the potential for negative effects following early-childhood interventions. The argument in favour of these interventions is that they offer higher returns than interventions later in children’s lives - but the flipside of this argument is that the costs of failure are likely to be higher as well. 

In other words, the potential payoff from early interventions relative to later interventions may be seen as a risk premium. 

To minimise the risk involved, it is of utmost importance that policymakers consider rigorous existing evidence and small-scale, randomised pilots before embarking on costly national reforms. Indeed, without precautions, such reforms may very well backfire spectacularly in ways similar to the Quebec childcare programme discussed here.

Gabriel Heller-Sahlgren is lead economist at the Centre for Education Economics (CfEE) and editor of its Monthly Research Digest. This blog is based on his editor’s selection for the March issue of the digest, published today. You can view, download and subscribe to receive it a free of charge here.

CfEE is an independent thinktank working to improve policy and practice in education through impartial economic research