There are frequent warnings about how expensive it is to have a child in the UK, but father-of-six and Sticking Up For Siblings author Colin Brazier says scare stories shouldn't detract from the benefits of children having siblings.

Financial service providers - and their press offices - like to treat us to bulletins about the cost of raising a child.

There are several studies each year and they peddle catchy acronyms like Cots (the Cost Of The Sibling).

But it would be naive to assume the authors of these reports are entirely disinterested. Most PR folk in the City are there to plug a product.

In recent years Cots estimates have been running well ahead of inflation. Recently the figure has been put around the £250,000 mark.

So I was relieved this week to see that the Child Poverty Action Group, in tandem with the Joseph Rowntree Foundation, had arrived at an estimate of £150,000. While still eye-wateringly high, it lacks the contraceptive impact of those quarter-of-a-million-pounds scare stories.

I say scare stories advisedly. Because all these studies usually ignore the way costs fall as family size rises.

There are economies of scale to offspring. It will set you back the same to run a bath for one child as it does for three. Children share heat and light, bedrooms and toys. Clothes are handed down.

Sibling discounts can be modest (hotel rooms), or worth thousands (private school fees). An older brother or sister can actually make childhood cheaper, by babysitting in loco parentis or reducing the need for a play-date or expensive excursion.

I've set out to recalibrate the cost/benefit analysis of family expansion, taking not as its starting point the fact that large families are a good thing, but the argument that simply giving an only child a sibling is demonstrably "worth it".

That assertion is the product of five years of work, much of it with Swedish researcher Therese Wallin. We found strong and, at times, compelling evidence, that belonging to a multi-child family has benefits.

Having a sibling while growing up can help a child resist allergies, obesity, and depression. 

Read more: http://www.bbc.co.uk/news/magazine-23778123 

Hmmm, what do YOU think based on your personal experiences?

I think I'll make this as the next poll too.