It might seem hard to believe, when you're in the fog of new motherhood, and every waking moment is devoted to feeding this tiny baby and rocking her to sleep.

It might seem hard to believe, when you have a runny-nosed toddler clutching at your legs, wailing if you try to walk away from him.

But becoming a parent makes you more productive at work. It's a fact.

And here's the proof: The Federal Reserve Bank of St Louis did a study involving 10,000 economists. It looked at research they'd had published in journals, and cross-referenced that with the number of children they had and when they'd had them.

What the study found was that female economists, understandably, had a dip in productivity when their children were young. But it was only temporary. Once the children reached their teens, these women were more productive than childless women their age.

Despite all the extra demands on their time outside of work, they were getting more done than their co-workers.

That's what parenting does to you. You don't realise it until your kids have grown up a bit, and you can really focus your energy back on work. But you find you're more committed, more focused, more efficient.

You're used to multitasking: breastfeeding, reading aloud and healing sore knees, so you can deal with having a dozen projects on the go. You're used to completely unreasonable demands, screaming tantrums and small people shoving beads up their noses, so you're not fussed by difficult colleagues.

You don't waste time, because you're not used to having time to waste.

What's more, you really appreciate work. You enjoy being able to use your brain for adult things. Work can almost become a guilty pleasure, with all those luxuries like someone else making your coffee, and being able to walk around without tripping on toys, and having an actual break for lunch. Oh, and achieving stuff. Achieving stuff feels good.

This is the secret that working mothers know. We are better workers in so many ways.

Sadly, employers aren't always aware of this. A study published in the American Journal of Sociology showed that when people were asked to hire fictitious candidates, mothers were discriminated against. They were offered starting salaries seven percent lower than applicants without children. They were seen as less competent and less committed.

Isn't it time to change that perception?