Paper 06 · Public money

137 Countries Are Building CBDCs. Three Things Most Are Not Designing For.

137 countries. 98% of global GDP. 49 live pilots. Three design questions most programmes are not answering.

Deepak Aggarwal · Posted 14 April 2026 · 16 pages
SSRN 6534119 · DOI 10.2139/ssrn.6534119

What this paper argues

Central bank digital currency programmes now cover 137 countries and 98% of global GDP, with 49 live pilots. The engineering is advancing faster than the decision architecture beneath it.

The paper identifies three things most programmes are not designing for, and reframes Nigeria's 98.5% unused-wallet outcome as a trust-architecture failure rather than a technology failure. A currency is a decision system before it is a payment rail.

Programmable public money raises the same question as programmable private money: when the protocol executes, can the issuing institution reconstruct what it decided?

Terms used here are defined once in the glossary: Decision Engineering™ · Decision replayability

Start with one decision

Name an important decision made in the last ninety days that your institution could not fully replay today — the rule that applied, the data that was live, the authority that permitted it.