Official statistics
As you may have heard, President Trump has dismissed the head of the US Bureau of Labor Statistics, claiming that payroll employment figures presented by the BLS were faked to make him look bad.
Politicians meddling with official statistics is a bad idea. This isn’t because official statistics are Pure and Holy and True and above mere political concerns; it’s because official statistics are messy and difficult and hard to get right, but also very valuable. The benefit-cost ratio of good official statistics is very high; for the NZ Census the ratio was estimated some years back as 10. National and local governments, non-profits, and businesses use official statistics to make decisions and the stock market responds to the numbers. On the other hand, the benefit-cost ratio of bad official statistics is very low — if no-one believes the numbers, there’s not a lot to be gained by publishing them. Since estimation is messy and difficult and hard to get right, trust in official statistics agencies is critical for trust in official statistics.
Agencies don’t always do it perfectly. It can definitely be necessary to have some sort of independent review at times. I was on the External Data Quality Panel looking at the 2018 NZ Census, and there has just been an independent review of the UK Office of National Statistics. The goal is to make sure the agencies have good procedures, evaluated carefully, to produce the best feasible answers. Political interference, on the other hand, is discouraged by national and international principles for official statistics. It’s hard to get rid of once you have it, and very hard to prove you’ve gotten rid of it — like black mould.
The American Economic Association put out a statement on Friday saying that getting rid of the BLS head this way was a bad idea. They don’t do this sort of statement very often. The International Statistical Institute put out a statement today — they do this more often, but it still takes a fairly significant event to get them moving. The American Statistical Association haven’t said anything yet, but they were all travelling to their annual conference over the weekend, so it might come soon.
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »