How to ensure non-negative nominal interest on your cash

John Cochrane writes:

So, quiz question for your economic classes: Suppose we have substantially negative interest rates — -5% or -10%, say, and lasting a while. But there is no currency. How else can you ensure yourself a zero riskless nominal return?

Here are the ones I can think of:

Prepay taxes. The IRS allows you to pay as much as you want now, against future taxes.
Gift cards. At a negative 10% rate, I can invest in about $10,000 of Peets’ coffee cards alone. There is now apparently a hot secondary market in gift cards, so large values and resale could take off.
Likewise, stored value cards, subway cards, stamps. Subway cards are anonymous so you could resell them.
Prepay bills. Send $10,000 to the gas company, electric company, phone company.
Prepay rent or mortgage payments.
Businesses: prepay suppliers and leases. Prepay wages, or at least pre-fund benefits that workers must stay employed to earn.

Comments section: how many more can you think of?

His conclusion:

The zero bound is not just cash.

More generally, he is discussing work by Kenneth Rogoff.