And your point is?

The costs of data quality failures are often very difficult to quantify, and, given the way that businesses operate, being unable to put a price tag on these failures usually means that they are given a low priority by organisations. Recently Amsterdam City Council made a data quality error which illustrates just how much they can cost.

There are at least seven different ways that numbers can be written around the world, with different symbols being used as decimal and as thousand separators. In the UK, for example, a decimal is indicated by a point and the thousands by a comma. In The Netherlands the reverse is the case. Without clarity and care about which format is being used, any resulting confusion can be the cause of numerous data quality problems.

Back to Amsterdam City Council. In processing rent relief payments for about 9000 Amsterdammers in late 2013 it appears that somewhere along the line the correct number format setting was overlooked or altered. The meanings of the commas and points were reversed when making the payments, so that each person received 100 times what they should have had. A person owed EUR 155, for example, received EUR 15500. The immediate cost of this simple error: EUR 188 million.

This is not the first time the municipality has been confused by number formats. Their website showed an expected income in 2014 of EUR 5880 billion (which is 950% of the Dutch gross domestic product and clearly wrong). What had been written EUR 5.880 billion should have been written EUR 5,88 billion, to match the normal Dutch number format.

On top of the immediate and obvious costs, data quality errors always have hidden costs. Amsterdam reversed the process and attempted to take back the money paid in error directly from the recipients’ bank accounts. This worked in most cases, but around EUR 4 million remains outstanding. People had already spent the money, it had been claimed by debt collectors, they had hidden it, or (in just 12 cases!) people had already paid the money back and are now EUR 31000 in debt. Without a ready solution for the 861 people where the money has not been able to be reclaimed, the municipality is having to find a solution on a case by case basis and are calling and visiting each person. The cost in manpower, time and communications is considerable. Beyond that are the costs to the already battered reputation of the municipality.

It’s easy to mix up your dots and your commas, but the costs can mount up.