Why Wages Have Stagnated While GDP Has Grown: The Proximate Factors

Real GDP per Capita & Median Weekly Earnings, 1980-2013

A.  Introduction

A healthy debate appears to be developing in the run up to the 2016 elections, with politicians of all parties raising the issue of stagnant wages.  Republicans have charged that this is a recent development, and the fault of Obama, but that is certainly not the case.  As the diagram above shows, real median wages have been stagnant since at least 1980, despite real GDP per capita which is 78% higher now than then.  Real median wages are only 5% higher (and in fact unchanged from 1979).  In a normally developing economy, one would expect real GDP per capita and real wages to move together, growing at similar rates and certainly not diverging.  But that has not been the case in the US since at least the early 1980s.

Why has such a large wedge opened up between worker earnings and GDP per capita?  This blog post will look at the immediate factors that lead from one curve to the other.  This will all be data and arithmetic, but will allow one to decompose the separation into several key underlying factors.  A future blog post will look at policies that would address those factors.

B.  Moving from Growth in GDP per Capita to Stagnant Real Wages

The progression from GDP per capita to real wages, with intermediate steps shown, looks as follows:

Going from GDP per Capita to Median Wage, 1947 to 2013:14

The chart here goes back further, to 1947, to show the divergence in recent decades in a longer term perspective.  The data come from the Bureau of Economic Analysis (BEA) or the Bureau of Labor Statistics (BLS).  As one sees, the curves moved together until around the mid-1970s, after which they began to diverge.

1)  Real GDP per Capita

Starting at the top, real GDP per capita (the curve in blue) measures the progression, in real terms, of GDP per person in the US.  GDP captures the value of all goods and services produced in the economy.  Its price index, the GDP deflator, is a price index for all those goods and services.  Although there have been temporary dips with periodic recessions, real GDP per capita has in fact grown at a remarkably stable long term rate of about 1.9% per annum going back all the way to 1870.  The growth rate was in fact a bit higher, at 2.0%, from 1947 to 2014, as the 1947 starting point was somewhat below the long term trend.  With this growth, real GDP per person was 3.75 times higher in 2014 than what it was in 1947.

2)  Real GDP per FTE Worker

But wages are paid to individual workers, and the share of workers in the population can change over time.  The share has in fact grown significantly over the post-war period, and in particular since about the mid-1960s, principally due to women entering the labor force.  There will also be demographic effects leading to changes in the shares of the very young and of retirees.

With a growing share of the population in the labor force, real GDP per full time equivalent (FTE) worker (the measure of the labor force used by the BEA) will grow by less than it will per person in the population.  The path of real GDP per FTE worker (the curve in green in the chart above), will rise more slowly than the path for real GDP per capita.  The curves start to diverge in the mid-1960s, when large numbers of women began to enter the labor force.

It should also be noted that the divergence in the two paths will not necessarily continue forever.  Indeed, the paths have in fact grown broadly in parallel from around 1997 until 2008 (when GDP per capita dipped in the downturn that began in the last year of the Bush administration).  The number of women entering the labor force reached a peak as a share of the labor force around 1997, and a decade later the first of the baby boomers started to retire.

Thus while such demographic factors and labor force participation decisions led to a significant divergence in the two paths (between GDP per capita and GDP per FTE worker) from the mid-1960s to the late-1990s, the impact since then has been broadly neutral, and might in fact go the other way going forward.

3)  Average Real Wages using the GDP Deflator

Next, workers are paid wages, not units of GDP.  Wages and salaries made up roughly half of GDP in 1947, with most of the rest accounted for by profits to capital.  And it stayed in the narrow range of 49 to 51% of GDP continuously until 1974.  The share then fell to 48%, where it held until 1981, and then began to deteriorate much more sharply, to just 42% as of 2013 (the most recent year with this data).

If the share of wages in GDP had remained constant, then the growth of wages per FTE worker would have exactly matched the growth of GDP per FTE worker.  But with a declining share of wages in GDP (with a growing share of profits as the mirror image), the curve (shown in brown in the chart above) of wages per FTE worker will rise by less than the curve of real GDP per FTE worker.

4)  Average Real Wages using the Consumer Price Index

The curves so far have been measured in real terms based on the GDP deflator.  The GDP deflator is a price index that takes into account all goods and services produced in the economy, and the weights in the price index will be in accordance with the shares of each of the goods or services in the overall economy.  But to an individual, what matters is the prices of goods and services that he or she buys.  This is measured by the consumer price index (cpi), where the weights used are in accordance with the expenditures shares of households on each of the items.  These weights can be significantly different than the weights of the items in GDP, as GDP includes more than simply what households consume.

The curve in orange in the chart above is then the average real wage but with the cpi rather than the GDP deflator used to account for inflation.  From 1978 onwards, the average real wage based on the cpi grew by significantly less than the average real wage measured in terms of the GDP deflator.  That is, inflation as measured by the items that make up the cpi grew at a faster rate, from 1978 onwards, than inflation as measured by the items (and their weights) that go into the GDP deflator.  Up until 1978, the cpi and the GDP deflator grew at remarkably similar rates, so the two curves (brown and orange in the chart) follow each other closely up to that year.

What happened after 1978?  The prices of several items whose weight in the cpi is greater than their weight in the GDP deflator began to rise more rapidly than other prices.  Especially important was the rise in medical costs in recent decades, but also important was the rise in housing costs as well as energy (with energy increases already from 1974).

Thus wages expressed in terms of what households buy (the cpi) rose by less, from 1978 onwards, than when expressed in terms of what the economy produces overall (the GDP deflator).

5)  Median Real Wages using the Consumer Price Index

The final step is to note that average wages can be misleading when the distribution of wages becomes more skewed.  If the wages of a few relatively well off wage earners (lawyers, say) rise sharply, the average wage can go up even though the median wage (the wage at which 50% of the workers are earning more and 50% are earning less) has been flat.  And that median wage is what is shown as the red curve in the chart.

[Technical Note:  The median wage series used here is the median weekly earnings of full time workers, adjusted for inflation using the cpi.  The series unfortunately only starts in 1979, but is the only series on the median, as opposed to average, wage I could find that the BLS publishes which goes back even as far as that.  The source comes from the Current Population Survey, which is the same survey of households used to estimate the nation’s unemployment rate, among other statistics.]

Since 1980 (and indeed since 1979, when the series starts), the median real wage has been flat.  This is not a new phenomenon, that only began recently.  But it is a problem nonetheless, and more so because it has persisted over decades.

C.  The Astounding Deterioration in the Distribution of Income Since 1980

Aside from demographic effects (including the impact of women entering the labor force), and the differential impact of certain price increases (medical costs, as well as others), the reason median real wages have been flat since around 1980 despite an increase of real GDP per capita of close to 80% over this period, is distributional.  The share of wages in GDP has been reduced while the share of profits has increased, and the distribution within wages has favored the better off compared to the less well off (leading to a rise in the average wage even though the median wage has been flat).

That is, the US has a distribution problem.  Wages have lost relative to profits (and profits largely accrue to the rich and wealthy), and the wages of lower paid workers have fallen even while the wages of higher paid workers have risen.

There are therefore two reasons for the distribution of income at the household level to have deteriorated since 1980.  And one sees this in the data:

Piketty - Saez 1945 to 2012, Feb 2015

This is an update of a chart presented in an earlier post, with data now available through 2012, and with the period from 1945 to 1980 included on the same chart as well.  The data came from the World Top Incomes Database (now part of the World Inequality Database), which is maintained by Thomas Piketty, Emmanuel Saez, and others.  The data is drawn from individual income tax return filings, and thus the distribution is formally by tax reporting unit (which will normally be households).  The incomes reported are total taxable incomes, whether from wages or from capital.

Over the 33 years from 1947 to 1980, average reported taxable incomes rose in real terms (using the cpi price index to adjust for inflation) by 87%.  The incomes of the bottom 90%, the top 10%, and the top 0.01%, rose by almost exactly the same amount, while the incomes of the top 1% and top 0.1% also rose substantially (by 57% and 63% respectively).  It is amazing how close together all these figures are.

This changed dramatically from 1980.  As the chart above shows, the curves then started to diverge sharply.  Furthermore, the average reported income rose only by 24% over 1980 to 2012, even though real GDP per capita rose by 73% over this period.  The 24% average increase can be compared to the 28% increase over the same years in the average real wage (based on the cpi).  While from two totally different sources of data (income tax returns vs. the national income accounts of the BEA) and measuring somewhat different concepts, these are surprisingly close.

But while average real incomes per household rose by 24%, the bottom 90% saw their real incomes fall by 6%.  Instead, the rich gained tremendously:  by 80% for the top 10%, by 178% for the top 1%, by 312% for the top 0.1%, and by an astounding 431% for the top 0.01%.

The US really does have a distribution problem, and this deterioration in distribution largely explains why real median wages have stagnated since 1980, while real GDP per capita grew at a similar rate to what it had before.

D.  Summary

To summarize, in the post-war period from 1947 to about the mid-1970s, measures of real income per person grew substantially and at similar rates.  Since then, real GDP per capita continued to grow at about the same pace as it had before, but others fell back.  The median real wage has been stagnant.

One can attribute this to four effects, each of which has been broadly similar in terms of the magnitude of the impact:

a)  Real GDP per worker has grown by less than real GDP per capita, as the share of those working the population (primarily women) has grown, with this becoming important from around the mid-1960s.  However, there has been no further impact from this since around 1997 (i.e. the curves then moved in parallel).  It may be close to neutral going forward, but was an important factor in explaining the divergence in the period from the mid-1960s to the late-1990s.

b)  The average real wage (in terms of the GDP deflator) has grown by less than real GDP per worker, as the share of GDP going to wages has gone down while the share going to profits (the mirror image) has gone up, especially since about 1982.

c)  The average real wage measured in terms of the cpi has grown by less than the average real wage measured in terms of the GDP deflator, because of the rising relative price since 1978 of items important in the household consumption basket, including in particular medical costs, but also housing and energy.

d)  The median real wage has grown by less than the average real wage (and indeed has not grown at all since the data series began in 1979), because of increasing dispersion in wage earnings between the relatively highly paid and the rest.

The implication of all this is that if one wants to attack the problem of stagnant wages, one needs to address the sharp deterioration in distribution that has been observed since 1980, and secondly address issues like medical costs.  Medical costs have in fact stabilized under Obama, as was discussed in a recent post on this blog.  But while several of the measures passed as part of the Affordable Care Act (aka ObamaCare) have served to hold down costs, it is too early to say that the previous relentless upward pressure of medical costs has ended.  More needs to be done.

Future blog posts will discuss what policy measures could be taken to address the problem of stagnant real wages and the deterioration in the distribution of income, as well as what can be done to address medical costs.

The Rate of Economic Growth and the Budget Gap: Returning to the Long-Term Average Growth Rate Would Eliminate It

Long Run US GDP per Capita Growth (1870-2088) in logarithms

Larry Summers published an op-ed yesterday (appearing in Reuters, the Financial Times, the Washington Post, and probably elsewhere) in which he makes the important point that the current budget impasse is focussed on the wrong issues.  The discussion, at least as publicly expressed, has focussed on what is seen as needed to deal with the fiscal deficit and the resulting public debt.  Even the Republican attempt to end ObamaCare was ostensibly about cutting the government deficit (even though the CBO concluded that the opposite would happen, as they found that the ObamaCare reforms will reduce the deficit, rather than increase it).

Yet this focus on near term and projected budget deficits is misguided.  As Summers notes, under current policies the public debt to GDP ratio is falling, and is projected to continue to fall into the 2020s.  The recently issued Long-Term CBO budget projections indicate that while the debt ratio would then start to rise (primarily driven by expected higher health care costs), there is a good deal of uncertainty in those projections.

Specifically the CBO figures show that it would not take much, in terms of either higher revenues or lower spending, to keep the public debt to GDP ratio flat.  Higher revenues or lower spending or some combination of the two, of 0.8% of GDP over the next 25 years or 1.7% of GDP over the next 75 years, would suffice.  This is consistent with an earlier post on this blog, which showed that if the Bush tax cuts had not been extended for almost all households, the projected debt to GDP ratio in the CBO numbers would fall rapidly.

But projections of revenues or of spending are highly uncertain.  Projected health care spending has been coming down steadily in recent years, for example, in part due to the slow economy, but also in part as a result of the efficiency gains and cost reductions that the ObamaCare reforms are leading to.  With these lower costs, the CBO has been steadily reducing the projected costs to the government budget from Medicare, Medicaid, and other such health programs.  In the recent CBO report, for example, the projections of government spending on health care programs in the 2030s were reduced by 0.5% of GDP from what the CBO had projected just one year earlier.  Going back further, the CBO projections for government spending on health care in 2035 were over 1% of GDP lower in the projections recently issued than in the projections published in June 2010.

This should not be interpreted as a criticism of CBO.  Their projections are probably the best available.  Rather, the point is that these projections are inherently hard to do, and the uncertainty surrounding them should not be ignored.  Yet the politicians often ignore precisely that.

Furthermore and perhaps most importantly, the projected budget deficits and resulting public debt to GDP ratios depend critically on the rate of growth of the economy.  The CBO uses a fairly detailed and reasonable model to project this (based on projected labor force growth, investment in capital, and productivity growth).  However, it is probably even more difficult to project GDP than to project future spending levels and tax revenues for any given level of future GDP.  But Summers notes the critical sensitivity of the projected future deficits to the projected growth in GDP.  He states “Data from the CBO imply that an increase of just 0.2 percent in annual growth would entirely eliminate the projected long-term budget gap”.

One can calculate from the data made available with the CBO report their projected growth of real per capita GDP.  For 2013 to 2088, it comes to 1.60%  year.  A previous post on this blog noted the remarkable constancy of the rate of growth of real per capita GDP since at least 1870 of 1.9% a year (or 1.87% a year at two digit precision).  That earlier post noted that real per capita GDP in the US, despite large annual variations and even decade long deviations (such as during the Great Depression, and then during World War II), has always returned to a path of 1.87% growth since at least 1870.  That path even did not shift when there were even substantial deviations, such as during the Great Depression.  Rather, the economy always returned to the same, previous, path, and not one shifted up or down.

This is truly remarkable, and no one really knows the reason.  The path can be seen as a trend growth of capacity (based on labor available and capital invested, coupled with the technology of the time), but why this should path should have grown at 1.87% a year in the late 1800s; in the early, mid and late 1900s; and all the way into the 21st century, is not known.

Since we do not know why the economy has always returned to this one path, we need to be careful in looking forward.  Still, it is noteworthy that the CBO projections imply that the economy will now slow, to just 1.60% real per capita GDP growth over the next 75 years.  This CBO path is substantially lower than the path of 1.87% growth that has ruled for the last 140 years in the US.

The graph at the top of this post shows the path of GDP per capita projected by the CBO (which one should note is a year by year projection, which just averages out to 1.60% per year over the full period), along with an extension of the 1.87% path that has ruled since at least the 1870s.   The graph is adapted from my earlier post (although now converted to prices of 2005 whereas the earlier one was in prices of 1990; this does not affect the rates of growth).  It is expressed in logarithms, since in logarithms a constant rate of growth is a straight line.

It is not clear why there should be this deceleration to 1.60% from the 1.87% rate of growth the economy has followed over the last 140 years.  Mechanically, one can ascribe the deceleration to what the CBO assumes for the rate of growth of technological progress.  But projecting growth in technology over a 75 year period is basically impossible, as the CBO notes.

The deceleration over the next 75 years has a very important implication, however.  The CBO found in its sensitivity analysis that a rate of growth that is just 0.2% faster will suffice to close the budgetary gap, even if one does not take any new measures to raise revenues or cut government spending.  Hence a return to the previous historical growth path of 1.87% a year from the 1.60% rate the CBO projects, or a difference of 0.27%, will more than suffice to close the budgetary gap.

The policy implication is that with such sensitivity to the growth in GDP, we should be focussed on measures to raise growth, rather than short term budgetary measures that will act to reduce growth.  The economy has suffered from government austerity since 2010, which has held back growth.  Government has been cutting spending, thus undermining demand in an economy with high unemployment and close to zero interest rates, where more labor is not employed and more is not produced because the resulting products could not then be sold due to the lack of demand.  As an earlier post on this blog noted, if government spending had been allowed to grow simply at the historic average rate (and even more so if it had been allowed to grow as it had under Reagan), the US would by now be back at full employment.

Over the medium term, Summers notes that both conservatives and liberals agree that growth should be raised, and on the types of measures which should help this.  More investment, both public and private, is required rather than less.  Research and development, both public and private, is important.  More effective education is also required.

I would agree with all of these.  But to be honest, since we do not really understand why the economy always returned to the 1.87% growth path over the last 140 years, it would not be correct to say we can be sure such measures will be effective.  However, what we can say with confidence is that measures that hinder the recovery of the economy, as the government spending cuts have been doing, will certainly hurt.

Multifactor Productivity Growth: A Record High in 2010

US Productivity Growth, Non-farm Business Sector, 1988- 2010

The Republican presidential candidates continue to assert loudly that over-bearing new regulatory burdens under Obama have crippled the American economy and account for the slow recovery from the 2008 collapse.  Mitt Romney, in a policy address at the University of Chicago on March 19 for example (see transcript here), asserted that regulatory burdens (in addition to higher taxes, even though taxes have in fact been cut under Obama), were leading to businesses shutting down and jobs disappearing as “Entrepreneurs decide it’s too risky and too costly to invest and to hire.”

New burdensome regulations, if they were a problem, would reduce productivity.  Yet as this blog has noted previously (see here), productivity growth has in fact been quite good during the Obama period.  The productivity concept normally used for such discussion is simple labor productivity, which measures output (GDP) per unit of labor input (either employment or hours of labor).  This productivity concept is useful in part because it can be estimated as soon as one has an estimate of GDP, i.e. each calendar quarter.  But it is not a measure of pure productivity, as output per unit of labor can rise due to several things, including from increased capital investment (more machinery and equipment, which improves productivity) or from changes in the composition of labor (towards more highly educated, and hence more productive, workers).

Multifactor Productivity (also sometimes called Total Factor Productivity) is a measure of productivity that takes into account increased capital availability and other such factors.   The Bureau of Labor Statistics of the US Department of Labor provides an estimate of it, but because it is more difficult to estimate, it only comes out with a major lag.  On March 21, the BLS issued its estimate for 2010.  Only annual estimates are made.  And while the series only goes back to 1987 (and hence has growth rates only from 1988), it is interesting that while Romney and the other Republicans are complaining of a large increased burden on business from regulations under Obama, the BLS found that multifactor productivity grew faster in 2010 than in any year since they started estimating the series in 1988.

The graph above shows the BLS estimates of multifactor productivity (MFP) growth for 1988 to 2010, for the private non-farm business sector.  MFP grew by 3.5% in 2010, reversing the downward trend seen since 2003 and absolute declines in 2008 and 2009.  As noted, the 3.5% increase in MFP in 2010 is the highest in the history of the series.  If Obama’s regulations were stifling businesses, one would not see such an upward bounce in productivity.  The Republican charge is simply not consistent with the facts.

One should also not jump to the opposite conclusion that the upward bounce in productivity in 2010 can be credited totally to regulatory or other reforms instituted by the Obama administration.  It would be consistent with such reforms improving productivity (i.e. the opposite of what Romney and the Republicans have asserted), but it could be due to other factors also.

The truth is that much of the year to year change in productivity can be accounted for by the business cycle.  When economic output is falling, as it was in 2008 and the first half of 2009, productivity will typically fall (or not grow as much as in normal growth years), as businesses lay off labor only with a lag after they find they cannot sell all of their output.  And in an economic recovery, productivity will rise, as businesses also only start to hire new workers with a lag.  The same happens with business investment (and hence the stock of machinery and equipment and other capital available for use), so that capital is underused as economic output falls in a recession and then is more intensively used at the start of a recovery.  Looking forward, it is likely that MFP growth will not be so high in 2011, and indeed might even be relatively low, as businesses started hiring new workers more aggressively in 2011 as the economic recovery continued (albeit slowly, due to still low demand for what they could produce).  But we will not know for another year, when the BLS issues their estimate for MFP growth in 2011.

The productivity data cannot by itself demonstrate conclusively whether or not the record high growth in productivity in 2010 was primarily due to measures implemented by the Obama administration.  But what we do know is that the data is clearly not consistent with the Republican charge that Obama has imposed huge new regulatory burdens which have stifled productivity.