GIGO

GIGO is the first rule of computing. It means, garbage in = garbage out. When I joined the bank in 1967 it had been computerising customer accounts for about two years. All the London branches were computer based when I started work.
Computers were big machines that needed tender loving care. 1960s TV shows like the Avengers, the Persuaders or Thunderbirds would portray them as big metal sided boxes with large reels of tape whirring around on the front. The modern mobile phone has more computer power than these monoliths, but they had to start somewhere.
The computers could process data faster than it could be inputted, certainly much faster than a human punch it in. The bank used punch tape to input the data. The branch could input the data throughout the day and transmit the tape via a phone line to the computer in the City.
Here's a picture I found on the internet. I hope the owners don't get too precious about me borrowing it to illustrate this post.

This picture shows the punch tape being loaded onto the first spool. Once loaded, the tape is fed through the reader and on to the second spool. Hit the start button and the machine reads the holes in the tape as binary code and is transmitted down the phone line. At the end of the transmission, the computer tells you if it received everything successfully.

Our branch had one of these terminals, and every day a courier van would arrive at about 5 o'clock with data spools from the sub-branches.These would be transmitted as well. Several (always male) members of staff formed a rota to stay late to transmit this data, and if you were lucky it took an hour. If there were errors in the data, you stayed until you found them, corrected them, and retransmitted the data.

So accuracy was essential.
The first law of computers is garbage in = garbage out.
The first rule of banking is credits must equal debits. Someone pays cheques and cash into their account. The various cheques and cash must add up to the total on the paying slip. That is fundamental and easily understood. Extend the principle so that every paying in slip when added together must equal all the cash received, plus all the cheques received. Simples.
Banks were built on trust. When a customer placed his money with a bank for safe keeping, the last thing he wanted was for the bank to lose sight of it, or be unable to account for every penny. Accuracy and numeracy were absolutely essential. It was the customer's money.

These days it's no longer the customer's money that keeps the bank in business. They keep in business by lending the bank's money to customers who have none. They stopped insisting that every cashier balance his till to the penny every day about thirty years ago.
I was working in retail at the time and each day I'd take the takings to be banked, and collect bags of change for the tills. I spoke to the cashier a week or so after the changeover from individually accountable tills to a system where the tills results were pooled. They never balanced from day one. They never did, ever again. Later again they stopped balancing the tills daily and only balanced them weekly. It might have saved time, I don't know.
What I did know was that numeracy (the ability to add up and take away) was declining alarmingly through the nation. Maybe the banks were forced into pooling the tills through a lack of quality staff.
What I did know was this. Every day, supposedly honest and trustworthy staff were buying their snacks using money from the till. It wasn't much, a few pence, but a principle had been lost.
If credits no longer equalled debits because of a few Mars bars, who made up the difference?

And did those who participated in, or oversaw and colluded with this petty dishonesty ever make their way to the top of the banking industry?