> Yep, but in the longer term (decades), all other things being equal a country that is saving 2% will have less investment taking place than that same country saving 5%.

Sure, but that means they are rather different economies. If one economy can save 5% it will - by definition of the identity - invest 5%, so it'll grow much faster. If it can find the demand to service, which directly leads back to the problem of consumption (spending vs saving).

The interest rate should be orthogonal to actually saving or spending. It just happens that since we want stability of prices, coins, notes, money in our accounts, and steady growth, instead of constant 2.00% central bank interest rate we vary the rate. If the central bank could simply rewrite a lot of numbers all around it could keep the base rate constant. But people would go mad, and people would come up with a new model that just translates back everything and blurts out the actual money supply and base rate changes.

Yes, there's talk about zombie corps, because money is cheap. But so is money to invest in new companies to compete with these zombies. Plus, if they don't make real money, then investing them makes no sense, buying their bonds make no sense, and extending them credit makes no sense, no matter how small the interest rate is. (Sure, they can live on smaller margins, but that doesn't make them literal zombies.)

Even in a negative interest situation creditors still need to price in risks. (People still need to pay them back on time. There's still administration and other kinds of overhead as you said.) For example the Danish mortgages are low risk, that's why the bank was able to offer them at negative rates. The moment negative interest rates start to seep into retail people will start to buy shit like there's no tomorrow. Which will push inflation up, and then the central bank moves out of the negative regime. And if all else fails, the central bank can simply buy government bonds, basically financing and encouraging public spending, which should open up the legislature to lower taxes, procure more stuff, etc.

> One problem is we don't have clear insight into how risky these loans are. If a bank is incentivised to give out loans just to avoid having to pay the central bank interest, it may end up taking on riskier loans than it otherwise would have (if it didn't think they were too risky, it would already have made them).

Agreed, yet in the face of deflation even risky busywork is better than nothing. At that point it's up to people, investors, speculators, legislators, to take risks and invest (to increase efficiency so more of the output becomes economic surplus which can be then spent/invested) or consume (to increase demand so investment becomes profitable).

The financial sector can scream all it wants about being squeezed tight, but it's not like they are the paragons of efficiency and foresight. Sometimes they are too risky (2008) sometimes they are too cautious (last year - all the talk about an impending recession, too long business cycle, etc.). And ultimately it's up to the population to prod their legislature to spend. (Related, but might be too cutting-edge: https://johnhcochrane.blogspot.com/2020/02/new-paper-fiscal-... - tl;dr a model that reproduces a lot of the empirical data, and shows how risk free return [gov debt] pays for itself)

The latest Eurostat report ( https://ec.europa.eu/eurostat/documents/2995521/10159412/2-2... ) states EU inflation is around 1.4%. (0.2 %points of that is energy, which is pretty much just natural resource extraction, and should be ignored, as it's not something that results in economic growth in the EU - I'd argue.) So still a bit far from the 2% mark.

But at least the curve inches up.

> Like how people kept buying computers during the 2000s even though the price of compute was halving every year.

Interesting example. A lot of people bought the new computer because it enabled different things. And "decommissioned" the old one because it got obsolete. The desire for new coupled with the low price (thanks to mass production of standardized components) allowed people to substitute their old computer, even though they had to pay the "transaction price" (the price of the new computer, plus setup).

Similarly some folks argue that a Tesla car is so much better all around and it just happens to be an EV. (Though they are pretty pricey, so mass adoption is not happening, but stock prices indicate that a lot of folks think it or something like that will indeed happen.)

Companies/businesses were relatively slow to replace their computers. The large technology churn was (and is) fueled by newcomers, and people replacing their old rig.

That said, I have no problem with experimenting with deflation (especially because I despise these dumb hard-limit policies like minimum wage - https://danluu.com/discontinuities/ ), just as I have no problem with negative interest rates (because our central banks [and models, interchangeably] seem to understand that better).