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.

Getty
Show Hide image

Richmond is a wake-up call for Labour's Brexit strategy

No one made Labour stand in Richmond Park. 

Oh, Labour Party. There was a way through.

No one made you stand in Richmond Park. You could have "struck a blow against the government", you could have shared the Lib Dem success. Instead, you lost both your dignity and your deposit. And to cap it all (Christian Wolmar, take a bow) you self-nominated for a Nobel Prize for Mansplaining.

It’s like the party strategist is locked in the bowels of HQ, endlessly looping in reverse Olivia Newton John’s "Making a Good Thing Better".

And no one can think that today marks the end of the party’s problems on Brexit.

But the thing is: there’s no need to Labour on. You can fix it.

Set the government some tests. Table some amendments: “The government shall negotiate having regard to…”

  • What would be good for our economy (boost investment, trade and jobs).
  • What would enhance fairness (help individuals and communities who have missed out over the last decades).
  • What would deliver sovereignty (magnify our democratic control over our destiny).
  • What would improve finances (what Brexit makes us better off, individually and collectively). 

And say that, if the government does not meet those tests, the Labour party will not support the Article 50 deal. You’ll take some pain today – but no matter, the general election is not for years. And if the tests are well crafted they will be easy to defend.

Then wait for the negotiations to conclude. If in 2019, Boris Johnson returns bearing cake for all, if the tests are achieved, Labour will, and rightly, support the government’s Brexit deal. There will be no second referendum. And MPs in Leave voting constituencies will bear no Brexit penalty at the polls.

But if he returns with thin gruel? If the economy has tanked, if inflation is rising and living standards have slumped, and the deficit has ballooned – what then? The only winners will be door manufacturers. Across the country they will be hard at work replacing those kicked down at constituency offices by voters demanding a fix. Labour will be joined in rejecting the deal from all across the floor: Labour will have shown the way.

Because the party reads the electorate today as wanting Brexit, it concludes it must deliver it. But, even for those who think a politician’s job is to channel the electorate, this thinking discloses an error in logic. The task is not to read the political dynamic of today. It is to position itself for the dynamic when it matters - at the next general election

And by setting some economic tests for a good Brexit, Labour can buy an option on that for free.

An earlier version of this argument appeared on Jolyon Maugham's blog Waiting For Tax.

Jolyon Maugham is a barrister who advised Ed Miliband on tax policy. He blogs at Waiting for Tax, and writes for the NS on tax and legal issues.