Parents are significantly less happy than non parents. It's true.

Look, we aren’t here to start a fight.

But researchers are again concluding that people without kids are happier than parents.

Often this is just accepted as a price parents have to pay for the long-term reward of raising children.

Except this time, clever social scientists have dug up why exactly parents are more stressed and paying this ‘happiness penalty’.

In a study to be published in the American Journal of Sociology, US researchers explored data from 22 European and English-speaking countries. including Australia.

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University of Texas sociology professor Jennifer Glass said they confined themselves to statistics from before the 2008 GFC to avoid confusing reports of happiness in a period of relative prosperity with reports taken in a period of economic stress.

“What we found was astonishing,” Dr Glass wrote.

“The negative effects of parenthood on happiness were entirely explained by the presence or absence of social policies allowing parents to better combine paid work with family obligations.

“And this was true for both mothers and fathers.”

Factors like unplanned pregnancies and large family sizes turned out to be of little importance.

Rather, improved family policies were 100 per cent the key to closing the parental happiness gap: generous paid parenting leave, increased paid sick and annual leave days guaranteed by law, lower childcare costs and more work flexibility.

In relief for us Aussies, Dr Glass told Mamamia our parental happiness gap was smaller than USA's massive 12 per cent. But the gap still sat at four per cent. Compare this to nations like Norway, France and Hungary, where parents are actually happier than non-parents.

Dr Glass said while the US was ranked dead last at 22 for its happiness gap, Australia came in 15th. New Zealand and the UK placed 18th and 19th respectively.

"Overall, the English-speaking countries don't come out on top," she said.

Childcare costs are seriously biting into the budgets of Australian families, and with the election only two weeks away, both major parties are pitching some long-awaited reforms, which you can read more about here. Better childcare = smaller happiness gap.

Dr Glass wrote that the most important happiness predictor for parents was the presence of family policies making it less stressful and less costly combine child-rearing with paid work.

She said countries with top-notch family policy packages, making it less stressful and less costly to both rear children and be employed, had no happiness gap between parents and the child-free.

What's more, she said good support policies for parents were not necessarily achieved at the expense of people without any kids in tow.

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"The policies that helped parents the most were policies that also improved the happiness of everyone in that country, whether they had children or not," she said.

"Policies such as guaranteed minimum paid sick and vacation days make everyone happier, but they had an extra happiness bonus for parents of minor children."

As the happiness of mums and dad, there were some differences between the two.

"Fathers’ happiness was slightly more sensitive to money policies - childcare costs, specifically - and mothers’ happiness was slightly more sensitive to time policies - especially paid sick and vacation days," Dr Glass explained.

Truly though, at a micro level, the jury is still out on whether individuals with kids are actually unhappier than the childless. Measuring happiness is a tricky business.

And there isn't much out there that can be more fulfilling than raising a little human.