Wage stagnation in the US: more than meets the eye

If you can, always look below the surface of data.

Via the Economist journalist Daniel Knowles comes a good example of why its important to look below the surface of statistics. American economist Steve Landsburg addresses a commonly heard refrain – that the wage of the median worker has barely risen in the past thirty years – and shows that all is not as it seems.

Landsburg cites a book by economist Edward Conard (first chapter, containing what we're talking about, here), which itself cites the Census Bureau. I confess that, without a more specific citation, I can't find the exact data Conard uses, but have found similar enough data (pdf, table A-5) to confirm the overall thrust of the argument.

Conard shows that from 1980 to 2005, median income in the US rose just 3 per cent once inflation is taken into account, from $25,000 to $25,700. 2005 is pre-crash, as well, so this isn't a tale of the recession.

But when you break the data down by race and gender, a very different story appears:

  1980 Median 2005 Median Increase
All Workers 25,000 25,700 3%
White Men 30,700 35,200 15%
Nonwhite Men 19,300 22,300 16%
White Women 11,200 19,600 75%
Nonwhite Women 10,200 16,500 62%

For every single demographic group, there was a much bigger increase in the median wage than we see when the groups are combined. The reason for this is obvious when it's pointed out: demographic change in the US means that there are far more (low-salaried) women and people of colour working now than there were in 2005, which pushes the overall average down.

Landsburg illustrates it with a farmyard analogy:

Imagine a farmer with a few 100-pound goats and a bunch of 1000-pound cows. His median animal weighs 1000 pounds. A few years later, he’s acquired a whole lot more goats, all of which have grown to 200 pounds, while his cows have all grown to 2000. Now his median animal weighs 200 pounds.

A very silly person could point out to this farmer that his median animal seems to be a lot scrawnier these days. The farmer might well reply that both his goats and his cows seem to be doing just fine, at least relative to where they were.

This is almost an example of Simpson's Paradox, a well-known (to stats nerds) effect where the direction of a correlation disappears when that correlation is disaggregated. I was taught it with an example involving racial discrepancies in application of the death penalty:

Sixty per cent of white murderers are executed for their crimes, and fifty per cent of black murderers. Are black people discriminated against in the application of the death penalty?

Now suppose that we break down the murder victims by race as well. We find the common pattern that people tend to attack victims of their own race:

Number of murders where death penalty is applied

White Murderer Black Murderer
White Victim 50/70=71% 25/30=83%
Black Victim 10/30=33% 25/70=36%

What about now? Does it begin to look like black people are discriminated against? In this example, black people are more likely to be executed for the murder of black or white victims; but because the murder of black victims isn't taken as seriously by the courts, the fact that murderers predominantly attack people of their race makes it look like black people are less likely to be executed than white people.

The median income example isn't quite a case of Simpson's Paradox, because there is still a positive increase in wage whether or not the statistics are disaggregated. But it's still an example of a time when it is best to dig beneath the surface.

But there is more to be said on the story of wage stagnation. Because a second claim normally accompanies the belief that US wages have stagnated, and that is that there has been a "decoupling" of wages. Due to rising inequality, the median household wage hasn't risen as fast as the mean wage:

If we've seen that the median wage grows faster when disaggregated, then the solid red line is likely to take a steeper ascent. But what happens to the dashed red line when disaggregated?

Sadly, I cannot find the data required to answer the question. If anyone knows where to look, tell me, and maybe we can put the issue to rest.

An immigrant worker protests in Orlando, Florida. Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

Photo: Getty Images
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The future of policing is still at risk even after George Osborne's U-Turn

The police have avoided the worst, but crime is changing and they cannot stand still. 

We will have to wait for the unofficial briefings and the ministerial memoirs to understand what role the tragic events in Paris had on the Chancellor’s decision to sustain the police budget in cash terms and increase it overall by the end of the parliament.  Higher projected tax revenues gave the Chancellor a surprising degree of fiscal flexibility, but the atrocities in Paris certainly pushed questions of policing and security to the top of the political agenda. For a police service expecting anything from a 20 to a 30 per cent cut in funding, fears reinforced by the apparent hard line the Chancellor took over the weekend, this reprieve is an almighty relief.  

So, what was announced?  The overall police budget will be protected in real terms (£900 million more in cash terms) up to 2019/20 with the following important caveats.  First, central government grant to forces will be reduced in cash terms by 2019/20, but forces will be able to bid into a new transformation fund designed to finance moves such as greater collaboration between forces.  In other words there is a cash frozen budget (given important assumptions about council tax) eaten away by inflation and therefore requiring further efficiencies and service redesign.

Second, the flat cash budget for forces assumes increases in the police element of the council tax. Here, there is an interesting new flexibility for Police and Crime Commissioners.  One interpretation is that instead of precept increases being capped at 2%, they will be capped at £12 million, although we need further detail to be certain.  This may mean that forces which currently raise relatively small cash amounts from their precept will be able to raise considerably more if Police and Crime Commissioners have the courage to put up taxes.  

With those caveats, however, this is clearly a much better deal for policing than most commentators (myself included) predicted.  There will be less pressure to reduce officer numbers. Neighbourhood policing, previously under real threat, is likely to remain an important component of the policing model in England and Wales.  This is good news.

However, the police service should not use this financial reprieve as an excuse to duck important reforms.  The reforms that the police have already planned should continue, with any savings reinvested in an improved and more effective service.

It would be a retrograde step for candidates in the 2016 PCC elections to start pledging (as I am certain many will) to ‘protect officer numbers’.  We still need to rebalance the police workforce.   We need more staff with the kind of digital skills required to tackle cybercrime.  We need more crime analysts to help deploy police resources more effectively.  Blanket commitments to maintain officer numbers will get in the way of important reforms.

The argument for inter-force collaboration and, indeed, force mergers does not go away. The new top sliced transformation fund is designed in part to facilitate collaboration, but the fact remains that a 43 force structure no longer makes sense in operational or financial terms.

The police still have to adapt to a changing world. Falling levels of traditional crime and the explosion in online crime, particularly fraud and hacking, means we need an entirely different kind of police service.  Many of the pressures the police experience from non-crime demand will not go away. Big cuts to local government funding and the wider criminal justice system mean we need to reorganise the public service frontline to deal with problems such as high reoffending rates, child safeguarding and rising levels of mental illness.

Before yesterday I thought policing faced an existential moment and I stand by that. While the service has now secured significant financial breathing space, it still needs to adapt to an increasingly complex world. 

Rick Muir is director of the Police Foundation