Ontario's Liberal government just promised "free" daycare for children aged two-and-a-half until they enter kindergarten (I use quotation marks around "free" because someone has to pay for it).

Let's set aside the questions about the timing of the announcement, mere months before a provincial election. More important is that the entire policy is based on the false idea that universal government-funded daycare is the way to go. We know that it is not.

Substantive research on Quebec, the one Canadian province that has had a provincial daycare system for many years, tells us as much. If anything, Quebec's system should serve as a warning to Ontario.

A recent conversation with Queen's University economist Dr. Steven Lehrer highlighted the fairly damning results of a study examining Quebec's system of highly subsidized daycare.

This award-winning research in 2005 by Baker, Gruber, and Milligan showed that maternal labour force participation rose in Quebec after the introduction of the then-$5-per-day daycare system (the cost has risen slightly since then), but that children were worse off on a number of different ways including "aggression to motor and social skills to illness." What's more, the study showed a rise in hostile parenting and worse parental health.

None of this made sense to Lehrer, who expected the opposite. So, Lehrer tasked a talented graduate student with replicating the results, which the student did in 2013. "The main result we found was that [the study] is 100 percent correct," Lehrer says. "It's robust. We actually find the effects get larger over time, on average."

Lehrer's research shows there are kids from single-parent households who do benefit from structured daycare. "But for most kids in the middle of the distribution from two-parent families, that is where we are getting these negative declines," he says.

In short, targeting child care at children and families who need it most would bring benefits, but offering so-called universal daycare to every family does not.

One of the reasons for this, Lehrer believes, is that group child care can't compete with the attention a child gets in other care situations. Simply put, kids growing up in homes where they might receive less attention benefit from daycare, but the majority of other kids end up doing worse.

Lehrer also notes that some parents also tend to think of child care too much as "early education," so they "do a lot less parenting, like reading to the child," he says.

There's also the issue of unequal access in systems like Quebec's, where children from wealthy families have been overrepresented in the publicly subsidized system. It's not hard to see why: demand spiked when the province first announced cheap daycare, which created waiting lists, which, in turn, parents from higher-income and generally well-educated and well-connected households learned to manipulate.

Economist Norma Kozhaya noted that in 2000, more than 58 per cent of children in subsidized daycares came from families with incomes above $60,000, even though they represented a minority of children four and under in Quebec. That trend continued for years until the province attempted a correction by setting fees to household incomes. It's a lesson to which Ontario would be wise to heed.

The Baker et al study did show that women's labour force participation increased in Quebec after the implementation of its universal daycare system: it went from around 74 per cent for prime-age women (aged 25 to 54) 20 years ago to 87 per cent now. And indeed, that's a big bump. But Canada's equivalent rate today is already 83 percent. A universal daycare system seems like a very expensive way to tease up labour force participation just a couple of points, especially considering there are other factors one can point to in explaining Quebec's participation rate.

Lehrer holds that daycare should be an issue of human capital development. That means quality spaces — not quantity — is of primary importance. For him, a compromise position involves targeting care to those who need it most. But above all, politicians and policy-makers, in Ontario and elsewhere, need to consider the research and set aside myths about Quebec's daycare system.

Says Lehrer: "For a policy where governments are spending billions of dollars, there is lots of evidence out there. This is high-quality work — it should not be ignored."