Friday thought experiment: Mac-PESA

I”m very wary of promulgating the “political correctness gone mad” meme, as it is so often a lazy reactionary knee-jerk response to changing times, but I could not resist tweeting about the news that a British police force launched an investigation after a man claimed he had been the victim of a “hate crime” when… a branch of the Post Office refused to accept his Scottish banknote. This incident has now indeed entered our official statistics as a hate crime.

Frankly, this is mental. Scottish banknotes are not legal tender, even in Scotland, as I have explained before. The Post Office is no more obliged to accept a Scottish Fiver than it is to accept Euros, gold or cowrie shells. The story did, however, cause me to reflect on what will happen when, post-Brexit, Scotland votes to leave the UK. Will Scotland then join the euro or create its own currency?

As supporters of Scottish independence insist, once Scotland becomes an independent country, it will be responsible for managing its currency in the same way that every other country that has its own currency is responsible for managing. But how should the Scots go about creating this currency? Surely messing around with notes and coins, other than for post-functional symbolic purposes, is a total waste of time and money.

A much better idea would be to go straight to the modern age and create Mac-PESA, which would be a digital money system rather like Kenya’s M-PESA with with a few crucial enhancements to take advantage of new technology. M-PESA, as a post on the Harvard Business School blog says, is “the protagonist in a tale of global prosperity to which we all can look for lessons on the impact of market-creating innovations”, going on to say that its “roots are far more humble”. They are indeed, and if you are interested in learning more about them, I wrote a detailed post about the origins of M-PESA (and Consult Hyperion’s role in the shaping of this amazing scheme) and the success factors.

The most important of these was the role of regulator: the Central Bank of Kenya (CBK) didn’t ban it. Conversely, one of the reason for the slow take-up of mobile payments (and the related slow improvement in financial inclusion) in other countries was the regulators’ insistence that banks be involved in the development and delivery of mobile payment schemes. The results were predictable. (Here’s a post from a few years ago looking at the situation in India, for example).

Anyway, back to M-PESA. It is an amazing success. But it is not perfect. In recent times it has gone down, leaving millions of customers unable to receive or send money. These failures cost the economy significant sums (billions of shillings), which not not surprising when you remember that M-PESA moves around 16 billion Kenyan shillings per day. So when it drops out, it leaves customers hanging, it leaves agents losing revenue and it leaves the banks unable to transact.

It is now vital national infrastructure, just as Mac-PESA would be.

So what if there were no system in the middle to go down any more? What if the telco, regulator and banks were to co-operate on a Enterprise Shared Ledger (ESL) solution where the nodes all have a copy of the ledger and take part in a consensus process to commit transactions to that ledger?

Do the math, as our American cousins say. Suppose there are 10,000 agents across Scotland with 100 “super agents” (network aggregators) managing 100 agents each. Suppose there are 10m customers (there are currently around 20m in Kenya, which has ten times the population of Scotland). Suppose a customer’s Mac-PESA balance and associated flags/status are 100 bytes.

So that’s 10^2 bytes * 10^6 customers, which is 10^8 bytes, or 10^5 kilobytes or 10^2 megabytes. In computer terms, this is nothing. 100Mbytes? My phone can store multiples of this, no problem.

In other other words, you could imagine a distributed Mac-PESA where every agent could store every balance. You could even imagine, thanks to the miracles of homomorphic encryption, that every agent’s node could store every customers’ balance without actually being able to read those balances. So when Alice sends Bob 10 Thistles (the currency of the independent Scotland), Alice connect to any agent node (the phone would have a random list of agents – if it can’t connect to one, it just connects to another) which then decrements her encrypted balance by 10 and increments Bob’s encrypted balance by 10, then sends the transaction off into the network so that everyone’s ledger gets updated.

You can have a 24/7 365 scheme without having a Mac-PESA system in the middle. When you make a transaction with your handset, it gets routed to a superagent who decrements your balance, increments your payee’s balance, and then transmits the new balances (all digitally-signed of course) to the other superagents.

 

It would be a bit like making an ATM network where every ATM knows the balance of every debit card. No switch or authorisation server to go down. And if an ATM goes down, so what? When it comes back up, it can resynch itself.

So please, someone challenge me on this. As a thought experiment, why not have Scotland grab a world-leading position by shifting to a Central Bank Digital Currency (CBDC) based on a shared ledger. I very much agree with the Bank of England’s view of such a thing, which is that the real innovation might come from the programmability of such a currency. This would be money with apps and an API, and I would hope that innovators across Scotland and beyond would use it create great new products and services.

One Reply to “Friday thought experiment: Mac-PESA”

  1. The primary reasons not to do this would be (a) you would need the central bank on side as you suggest, and central banks are typically more loyal to banks and other central banks than their own people; and

    (b) this proposal would start a foodfight amongst the consultants, SIs, blockchainers, telcos, FATFas and all the other single-agenda players.

    The result would be a race horse designed by a committee, a.k.a. a camel. Which doesn’t survive well in Scottish climate.

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