Contracts in a deflationary currency can and will account for the deflationary nature of the currency. For instance if the real interest rate you wanna charge s

Contracts in a deflationary currency can and will account for the deflationary nature of the currency. For instance if the real interest rate you wanna charge someone is 10% and currency is deflating at the rate of 5% then you'd charge the individual 4.5% interest rate.