There are lots of talking points around whether the UK should remain in the EU. I want to get to the seat of one burning issue.
On The Andrew Marr Show today, discussing the referendum, Iain Duncan Smith, the Work and Pensions Secretary, said he was worried about British plumbers and electricians being "undercut" by workers from elsewhere in the EU.
But plumbing and electricity services can only be delivered in person, meaning everyone competing to provide those services faces the same living costs (unlike for telecoms services) - with the exception of the cost of supporting dependents. It costs less to support children living in Bulgaria than children living in London.
There are at least two solutions to this problem: stop British people having to compete on costs, as IDS wants, or support them to compete with a benefits system, specifically child tax credits.
Why might the second option be better? Because it's more progressive.
If you want to renovate your bathroom along the theme of a Roman thermae, filling your bath from the teats of a golden Venus, then you probably want the very best quality workmanship - no chipped nipples or asymmetrical streams of hot and cold to tarnish the effect. And you can get that, by paying through the nose for the plumber best able to handle lovely Venus, helping that plumber to build an empire and thermae of their own.
But if all you want is your bog repaired, cost is your main concern.
Under a protectionist policy like IDS advocates, everyone who wants their bog repaired has to support the plumber's kids to the same extent, regardless of whether they wipe their arse with Morrison's own-brand paper or quadruple-quilted Andrex.
Whereas, under a system of tax-based support, those who buff their anuses to a high sheen with the under-feathers of fattened geese contribute more to little Jim and Jane's alphabetti spaghetti than those who have to wait for the burn to subside before they can sit down after taking a squat.
IDS would prefer to see the goose baskets of the wealthy brim-full with goslings, whereas I'd like everyone to be able to take the weight off immediately after a strainer.
Where do you sit?