At the moment, the base rates in the UK are well below inflation, it's entirely possible to get a mortgage (for instance) at a rate lower than inflation, eroding the debt in real terms.

The wage thing is a red herring, and has effects regardless of the currency model.

Base rate is below inflation but you try and find a mortgage at that rate. HSBC currently have a fixed rate mortgage at 1.94% for 2 years, base rate is 0.25%. Inflation is currently at 2.9% so you could get a mortgage where the debt is eroding in real terms however I am not sure why you would disregard wage inflation this scenario, wages are required to pay the mortgage, and whilst there may be other factors involved wages inflating a slower rate than general inflation means that the "real term" debt reduction we are discussing is practically non-existent for most people.

I disregard wage inflation in this scenario because we are comparing inflationary and deflationary currencies. In either case if the change in your wages doesn't stay above the change in value of the currency you're stuffed.

i.e. it's not a property of the money.

But it is a property of the money. Part of the reason why inflation is a policy is that it supposedly creates jobs, which is why professional economists fret about stagflation threatening their vaunted models. The way that inflation theoretically props up jobs is by reducing the real value of labor[0]... So wage erosion is fundamental raison d'être of the currency.

A cynic would argue that the policy works because a good way to enforce employment is by forcing people to stay afloat.

[0] https://krugman.blogs.nytimes.com/2010/02/13/the-case-for-hi...

Ah I see, then yes theoretically you can borrow and watch low interest rates and high inflation erode the value of the debt.