But you were just saying (or relaying the point that) the inflation tax is good because it changes people's behavior in the way of spending sooner. If "there's no evidence that modest inflation causes people to spend money sooner", then it fails by the very metric you suggested.

You can't have it both ways: either inflation (of a certain rate) is good because it makes people spend sooner, or it doesn't change behavior.

Edit: or there's some other way in which you operationalize the goal of "increased economic activity" that's orthogonal to "spending earnings sooner than you otherwise would".

Perhaps because I am using my terms loosely. My apologies.

By spending I intended "purchasing depreciating (or disposable) assets"

Purchasing equities as an inflation hedge is not what I meant. Inflation does encourage riskier investments, as merely holding currency is insufficient to maintain capital.

I agree that it's an open question whether or not that's a good thing: some would argue that encouraging riskier investments encourages malinvestments which becomes a net negative; others argue that the increased activity caused by risky investments outweighs the damage done by malinvestments; I've even run into many who claim that even malinvestments are good, since moving money around is good no matter the reason.

If that last point of view is true, I'm giving up on economics, but the first two both seem reasonable to me.

Depreciating vs investment assets is orthogonal; both lose value more slowly than money in a hyperinflationary situation.

And yes, there are trade offs, one of which is the malinvestments from spurring people to hold non cash. My point was that this, plus the individual welfare loss of the hoarder from having to commit to purchase sooner, must be weighed against the purported benefits of (what you got people to do via) inflation -- and (as I said at the beginning) that most people who make that argument for inflation (even economists) don't offer a way of modeling those relative benefits.

It's like arguing for an apple subsidy on the basis that apples are good, without even thinking about the costs of such a subsidy (ie diversion from non-apple production).