Pay Power
Speech given by
Andrew G Haldane
Chief Economist
Bank of England
Acas "Future of Work" Conference
Congress Centre, London
10 October 2018
The views expressed here are not necessarily those of the Bank of England or the Monetary Policy
Committee. I would like to thank Will Abel, Shiv Chowla, Tomas Key, Brad Speigner and Ben Stokes
for their help in preparing the text. I would like to thank Ben Broadbent, Clare Macallan, Becky Maule,
Mette Nielsen, Silvana Tenreyro and Jan Vlieghe for their comments and contributions.
This work contains statistical data from ONS which is Crown Copyright. The use of the ONS statistical
data in this work does not imply the endorsement of the ONS in relation to the interpretation or
analysis of the statistical data. This work uses research datasets which may not exactly reproduce
National Statistics aggregates.
whose theme this year is the "Future of Work".
It is great pleasure to be here at the Acas Annual Conference
particular pleasure to have Brendan Barber as Chair. As a member of the Bank of England's Court
It is a
Brendan's insights on the labour market and
between 2003 and 2012, wider economy were crucial in helping
the Bank steer a policy course through a period of first macroeconomic calm and then extra-ordinary
macroeconomic storm following the global financial crisis.
It is the labour market that I want to discuss today. We have seen an unusual pattern emerge here over
recent years. Jobs growth has been strong, with over 2 million new jobs created since the end of 2012. But
pay growth has remained weak by historic standards, averaging around 2% annually. This pattern has been
replicated across a number of other advanced economies. As we reach the anniversary of what has become
a "lost decade" for
inflation-adjusted pay in the UK, it is a good time to take stock.
What explains this puzzling pattern of rich jobs but poor pay growth? Some of the reasons for weak pay
have been cyclical. The financial crisis caused large job losses. A significant pool of unemployed workers
UK's economic recovery has
emerged and job insecurities rose, depressing pay growth. Recently, the
shrunk the pool of unemployed workers and reduced somewhat job insecurity. Had these cyclical factors
been the only ones at work, we might have expected a stronger recovery in pay.
The reason we have not is because longer-term, structural forces have also been holding back pay growth,
notably weak productivity. Over the medium-term, productivity is the single most important determinant of
the national income pie. Productivity growth pays for pay rises, at individual firms and for the economy as a
whole. Over the past ten years, productivity has barely grown in the UK. That second "lost decade" goes a
long way towards explaining the lost decade in pay.
Productivity is not, however, the only structural factor at work in the labour market. The world of work is
being reshaped in many advanced economies by the secular fall in the degree of unionisation and collective
bargaining, by changes in employment contracts and working patterns and by rises in the degree of
workers' "pay
concentration and automation in the company sector. By reducing power", they too have
depressed wage growth, actually and prospectively.
I will start by discussing recent pay developments and the factors responsible for driving them, cyclical and
structural. I will then discuss the implications of these cyclical and structural factors for domestic cost
growth, inflationary pressures and hence for monetary policy in the period ahead.
Jobs and Pay
I do not need to tell this audience that the past decade has been a strikingly weak one for pay growth. Ten
years ago, the mean weekly wage in the UK was around £435 per week. A decade on, it has risen to £520
per week, an average annual rise of less than 2% in money terms. This makes it the weakest decade for
growth in money wages for British workers since the 1930s.
That is not the end of the story, of course. Over the same period, consumer prices in the UK have risen by,
on average, 2.2% per year. That means inflation-adjusted, or real, pay has fallen by around 3.7%
cumulatively over the past decade. That weekly pay packet in 2008 has, in purchasing power terms, fallen to
be worth only around £420 per week.
This makes the recent period very unusual by historical standards (Chart 1). Since as far back as 1870,
there have been only two episodes when the real pay of workers has fallen over a ten-year period. The
other episodes were associated with seismic shocks in the labour market, often wrenching technological
change or sharp cyclical downturns, which raised levels of unemployment and job insecurity.
The past decade has bucked that historical trend, with a boom in job creation accompanying weak pay
growth. The employment rate in the UK has risen to over 60%, and the unemployment rate has fallen to 4%,
respectively their highest and lowest levels since the mid-1970s. The vast majority of these new jobs,
around 75%, have been full-time. And this boom has persisted, with around 830,000 job vacancies currently
-
being advertised the highest since records began.
This picture of weak pay and strong employment has been broadly-based, spanning all regions and sectors.
Real pay has fallen across every region of the UK since 2008 (Figure 1) and in all three major sectors of the
economy (Chart 2). Meanwhile, unemployment has fallen steeply across every region of the UK, by at least
2.5 percentage points.
The high-level picture of the UK labour market, then, is a jobs-rich but pay-poor recovery. This pattern is
broadly replicated in other countries. For example, there is a striking correlation between the pattern of
unemployment and wage growth in the UK and the US (Charts 3 and 4). In the US, unemployment has
fallen to its lowest levels since 1969, while pay growth has remained modest.
Given the strength of jobs growth, the weakness in pay has surprised many people, including the
plots the Bank's wage forecasts at annual intervals since
Bank of England. Chart 5 2012. Over this period,
there has been a sequence of negative forecast errors, averaging around one percentage point per year.
The same has been true of external wage forecasts, for the UK and elsewhere. These surprises suggest
that the recent pattern in pay and unemployment has been unusual by historical standards.
In the 1950s, A W Phillips uncovered a negative empirical relationship between pay growth and
unemployment: pay grows faster when unemployment is lower. The Phillips curve was born (Phillips
(1958)). This relationship has since become a central pillar of macro-economic theory and policy. Part of
the attraction of the Phillips curve lies in the fact that it tells a simple story: the tighter the jobs market, the
greater the pressure on pay.
Exactly 60 years on, the Phillips curve is still widely used, and widely debated, by economists and
policymakers. But with pay undershooting expectations, and with unemployment touching generational lows,
some big questions are being posed of it. Has the Phillips curve died of old age, or is it merely sleeping?
Has it changed shape or location? The juries (or coroners) have yet to reach a definitive verdict.
There have been a number of recent re-examinations of the evidence.1 Using different datasets and
techniques, these have tended to conclude that the Phillips curve has a pulse and remains alive and kicking.
As an illustration, Charts 6 and 7 plot the relationship between wage growth and unemployment in the UK
and the US over three sample periods dating back to the 1970s. They also plot some simple regression
lines of best fit.
All of the regression lines are negatively-sloped and, for the UK, statistically significant. Across the three
samples, the estimated Phillips curves are similarly-sloped.2 These curves have, however, shifted
downwards significantly over time. Taken together, this evidence is consistent with the Phillips curve having
a pulse that is beating at a similar rate to the past, despite the patient having moved hospital.
Explaining the Pay Puzzle
To explore the behaviour of pay in greater detail, we can use a slightly more sophisticated model which takes
account of factors in addition to unemployment. Table 1 provides some econometric estimates of pay
relationships over the period 1992 to 2018. The factors determining pay growth can be grouped under three
headings, each of which is important in explaining its evolution over the (distant and recent) past.
One key factor affecting pay growth is inflation or expectations of inflation.3 This makes intuitive sense. In
the end, workers are interested in the purchasing power of their pay, not its money amount. They bargain
over real wages. So inflation, or its expectation, affects pay with a coefficient close to one. Put differently, in
the course of wage bargaining, employers insure workers against inflationary shocks, at least on average.
Movements in inflation have been a key driver of pay growth historically. They are the main reason why the
Phillips curve shifted downwards significantly as the Great Inflation of the 1970s gave way to the Great
Moderation of the late 1990s. That period saw inflation expectations ratchet down to target levels where they
have remained anchored since (Chart 8). Pay growth has, in response, fallen pretty much one-for-one. This
explains the first downwards shift in the Phillips curves shown in Charts 6 and 7.
1
For example, Coibion and Gorodnichenko (2015), Gordon (2013), Vlieghe (2018), Saunders (2017) and Tuckett (2018).
2
In statistical terms, you cannot reject the null that their slopes are the same.
3
Both measures have a statistically significant impact on wage growth. The regressions in Table 1 use inflation expectations as they
give a slightly better empirical fit.
A second key determinant of wage growth is unemployment or, more precisely, the gap between
unemployment and its longer-run trend (sometimes called the NAIRU or Non-Accelerating Inflation Rate of
Unemployment).4 The larger this unemployment gap, the weaker the upward pressures on pay growth, as
A W Phillips had first postulated 60 years ago.
In econometric wage equations, the unemployment gap is a (statistically and economically) significant
determinant of pay (Table 1). A 1 percentage point unemployment gap drags on wage growth by around
0.8 percentage points. That means the 2 percentage point narrowing in the UK unemployment gap since
2012 would be expected to have raised wage growth by 1.6 percentage points, a significant tailwind.
The NAIRU itself is unobservable. It is also moveable, depending on structural features of the labour market.
This means the NAIRU needs to be estimated and these estimates are apt to shift over time. Over recent
years, the Bank has revised down its estimate of the NAIRU in the UK, by just under a percentage point, to
around 4 1⁄4%. These downwards surprises to the NAIRU (upwards revisions to the unemployment gap) help
Bank's
account for the persistent overshoot in the wage forecasts.
There are a variety of alternative, complementary measures of slack in the jobs market. For example, the
number of hours a person works, relative to their desired hours, is also relevant to gauging the degree of
spare capacity in the labour market. A number of research papers, theoretical and empirical, have found that
such
"under-employment" may also have a significant bearing on the setting of pay.5
There are various measures of under-employment, including the proportion of the workforce working
part-time involuntarily and the gap between actual and desired hours worked. In practice, these two
measures exhibit a very similar pattern (Chart 9). They also track the unemployment rate closely. This
suggests the incremental information contained in measures of under-employment, relative to measures of
unemployment, might be relatively modest.
Econometric estimates confirm that impression. Replacing the unemployment gap with a measure of the
under-employment gap produces a very similar wage equation (Table 1).6 And in a pairwise comparison,
under-employment is statistically insignificant if the unemployment gap is included. Under-employment is
important for pay, but does not appear to much improve the explanation of recent wage dynamics.
A third factor determining pay pressures is productivity. It is through gains in productivity that individual
firms, and the economy at large, can finance increases in workers' pay. Econometric estimates confirm that
intuition. The productivity of the labour force is a (statistically and economically) significant determinant of
pay (Table 1). On average across firms, a 1 percentage point rise in productivity raises aggregate wage
growth by around 0.8 percentage points.
4
Espinosa-Vega and Russell (1997) provide a history and review of the NAIRU concept.
5
For example, Bell & Blanchflower (2018).
6
Specifically, the involuntary part-time share of employment.
Productivity growth in the UK has consistently surprised to the downside since the crisis, averaging 0.5% per
year since 2010 or around 1.5 percentage points below its historical average. We would expect weak
productivity in turn to have been reflected in lower pay growth. Consistent with that, the fall in productivity
growth since the crisis largely explains the (second) downward shift in the Phillips curve (Charts 6 and 7).
Since 2012, the Bank's forecasts have consistently over-estimated productivity growth, on average by just
This suggests a sizable fraction of the Bank's negative
under 1 percentage point per year (Chart 10).
forecast errors for wages might plausibly be explained by downside surprises to productivity, alongside the
effects of a lower than expected NAIRU. Had the Bank known a decade ago how weak UK productivity
growth (and how much lower the NAIRU) was likely to be, its forecast errors for wages would have been
smaller.
We can confirm this by re-running our pay equations substituting in the actual outcomes for inflation, the
unemployment gap and productivity growth, in place of the forecasts for these variables at the time
(Chart 11). The fitted values for wage growth now track actual wage growth reasonably closely. With perfect
foresight about its determinants (productivity, unemployment and the NAIRU), there would have been far
less systematic over-estimation of pay growth during the lost decade.
UK's
This suggests the lost decade for real pay can, to a significant extent, be accounted for by
macro-economic developments: cyclically, the large pool of unemployed that built up immediately after the
crisis, generating a drag from the unemployment gap; and structurally, from lower levels of productivity and
a lower NAIRU than in the past. With those accounted for, there is far less of a pay puzzle left to explain.
The Wage Bargaining Game
A more granular look at the labour market suggests, however, that it is not behaving identically to the past.
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Tectonic shifts in the labour market - cultural, contractual, technological, organisational have come thick
and fast recently. Because this structural change is slow-moving, it is difficult to detect in monthly pay
movements. On a longer fuse, however, empirical evidence suggests these seismic shifts in the jobs market
are influencing pay significantly.
The Phillips curve plots the relationship between the stock of unemployed and wage growth. Another strand
of the labour market literature has looked instead at flows of people into and out of work and the associated
process of job-matching between employers and employees.7 In these models, pay is determined by flows
of workers between jobs, and by the relative bargaining strength of employees and employers, as well as by
fluctuations in labour demand and supply.
7
For example, Moscarini and Postel-Vinay (2017).
Flows of workers and their bargaining power are, in turn, affected by structural features of the labour market.
A rise in job insecurity will reduce flows of workers between jobs and their bargaining strength. A fall in the
degree of unionisation and collective bargaining degree of automation
in the labour market, and a rise in the
will also reduce workers' pay
and concentration in the company sector, power. We discuss each in turn.
workers'
If these structural forces were reducing bargaining power, we might expect them to receive a
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declining share of the income pie a fall in the "labour share". Internationally, there is strong evidence of the
labour share having fallen across a large number of developed countries.8 Structural factors, such as rising
levels of automation and falling rates of unionisation, are typically found to have been an important
contributor to those falls in international labour shares.9
At face value, the UK appears to have bucked those trends. Chart 12 plots the UK labour share since 1955.
Over the past two decades, it has been broadly flat. The UK labour share in 1990 was 50%, largely
unchanged from today. In the UK, there appear to be fewer signs of any significant shift in the bargaining
power of workers having resulted in them taking away a smaller slice of the income pie. I will discuss some
of the reasons for that below.
But we also need to be cautious when interpreting the labour share. First, looked at over a longer horizon, it
has been a fall in labour's share of income
is clear there in the UK over the past 60 or so years. Since 1955,
the labour share has fallen by around 10 percentage points, falling sharply during the 1970s and 1980s.
Moreover, the level of the UK labour share today, at 52%, is similar to advanced economies as a whole
(around 51%), many of which have experienced falls more recently.10
Second, looking at the sources of labour income is also important. These comprise not only wages and
salaries, but also defined-benefit pension contributions from companies and social contributions. While
technically-speaking these are all income, they are not always equivalent when it comes to thinking about the
wage bargaining process and spending patterns. The distribution of these different sources of income may
also be uneven across cohorts of workers.
Take defined-benefit pension contributions. For those still in work, these are deferred income that cannot
easily be spent today. With most defined-benefit schemes having closed, this income also only accumulates
to a subset of (mostly older) workers. As these pension contributions have risen recently as a share of total
income, the resulting boost to labour income will have been spread unevenly across generational cohorts
and the increase in the average worker's true purchasing power may have been exaggerated. If we strip out
back payments made by firms to fill pension deficits, the labour share shows greater signs of falling, if only
gradually, over time (Chart 12).
8
IMF (2017).
9
IMF (2017).
10
IMF (2017).
tracks workers' purchasing power,
A more stripped-down measure of the labour share, which better is wages
and salaries (Chart 12). That measure has fallen by around 1 percentage point since 1990. This picture is
more striking still if we look at different cohorts. For workers aged over 55, their share of income has
doubled from 4% in the early 1990s to 8% today. For workers aged 16-34, their wage share has fallen from
The "lost decade" for young people has been
15% to 12% over the same period. particularly pronounced.
Finally, aggregate movements in the labour share can obscure important pay dynamics at the sectoral level.
Different sectors of the economy are affected to differing degrees by changes in the form of employment,
technology, unionisation and company concentration. As I discuss below, these sectoral data provide a
on workers'
clearer picture of the significant impact of slow-moving structural factors pay power.
(a) Job Market Flows
The quickest way to secure a pay rise is by moving job. That is quite sobering if, like me, you have never
jobs ("twisters") has exceeded
moved job. Pay growth of UK workers moving that of workers remaining in
their position ("stickers")
by 4 percentage points since 1994 (Chart 13). When workers exercise the outside
option of moving between jobs, this puts upward pressure on pay through two main channels.
The direct, or arithmetic, effect arises from moving workers securing a pay rise and boosting the batting
average for overall wage growth. More twisters means higher average pay. The indirect, or behavioural,
effect arises when companies pay higher wages to existing staff, as well as new staff, to encourage them to
stay rather than exercise their outside option. The threat of twisting can also boost pay.
This flow-based model suggests a slightly different specification of the Phillips curve. The flow of workers, as
well as the stock of unemployed, may matter for pay growth. Sure enough, if we replace the unemployment
gap with measures of voluntary job-to-job flows, this provides a (statistically and economically) significant
explanation of wage growth (Table 1). As with under-employment, in a statistical horse-race between the
two measures the unemployment gap does slightly more of the donkey work.
Flows between jobs also provide a useful framework through which to explain recent pay developments.
Chart 14 plots voluntary job-to-job flows in the UK recently. The global financial crisis raised unemployment
-
and job insecurity. With workers fearful of unemployment and employers having less need to attract
-
workers given the large pool of unemployed voluntary job moves plummeted, falling from around 1% of the
working population pre-crisis to a low of around 0.5% in 2009.
As the economy and jobs market has recovered, and job insecurity has fallen, more people have voluntarily
moved jobs to secure a higher wage. Job-to-job flows today are back to their pre-crisis averages. In this
tightening market, the pay growth of "twisters" has picked up markedly, from a little under 4% in the
aftermath of the crisis to over 7% now.11 Through the direct (batting average) channel, this has in turn
boosted aggregate pay growth.
More surprising, however, is how little impact strong employment has had on those not moving job. Wage
"stickers" has
growth for flat-lined at around 2%. Despite a tightening labour market, companies have so far
not felt compelled to pay-up to any significant degree to retain workers. The indirect, or behavioural, channel
for pay pressures has largely been missing during the recent jobs recovery.
This may be a sign that stickers' pay is behaving differently than in the past. Chart 15 plots two empirical
-
Phillips curves one for twisters, the other for stickers. The twisters' Phillips curve is behaving relatively
similarly to the past, with pay broadly as expected given the tightness in the jobs market. But the Phillips
curve for stickers looks to be somewhat flatter, and the rise in pay somewhat weaker, than might be
expected given labour market tightness.
Why might companies have felt less need to pay-up to retain staff than in the past? Equivalently, why might
the pay power of existing workers have fallen? One possible explanation is recent change in employment
contracts. Although the cyclical degree of job insecurity has fallen as people have become less fearful of
losing their job, there may have been a compensating rise in structural job insecurity as people have become
more uncertain about their hours and income in a job.
There are various dimensions of employment contracts and different metrics of their impact on job security.
One commonly-used measure is the share of the working population self-employed, doing agency work or on
temporary or zero-hours contracts. The share of workers in each category has risen significantly recently.
For some, these shifts in employment contract are welcome as they bring increased job flexibility.
For others, they may be less welcome. The dark side of job flexibility is increased income uncertainty and
job insecurity. It is estimated that more than one in ten of those on part-time contracts would prefer full-time
work and close to half of those on zero-hours contracts would prefer to be on fixed-hours contracts. At the
same time as the quantity of work has risen, for a growing number of workers its quality may have fallen.
This pool of poorer-quality work appears to be fairly deep. For example, around a quarter of those in
temporary work say they could not find a permanent job and over 10% of part-time workers say they could
not find a full-time job.12 A Skills and Employment Survey published just last week found around 1.7 million
workers might be suffering from high levels of anxiety about their uncertain hours of work.13
One of the side-effects of structurally-higher job insecurity is a reduced willingness to add to that uncertainty
by moving job. If so, this would mean "twisters" are fewer in number than in the past and that stickers are at
11
Note that data for pay growth for "stickers" and "twisters" is annual, with latest estimates to 2017.
12
Taylor (2017).
13
Skills and Employment Survey (2018).
an even greater pay disadvantage to twisters as their outside option has lost value. In short, job insecurity
workers' pay power and
reduces weakens upward pressure on pay.
Empirical evidence is consistent with that. Even after controlling for different occupations and locations,
self-employment has been found to result in a wage discount for workers of around 15%.14 Temporary
contract workers face a wage discount of around 5-6% and agency workers of around 2 1⁄2%.15 Zero-hours
contract workers suffer a wage discount of around 7%.16
A second implication of structurally lower pay power is that there is greater scope for employers to
differentiate between workers in their pay awards. If companies are less fearful of losing talent, they will no
to pay a across their firm to
longer feel obliged "going-rate" maintain staff numbers. The flat-lining of stickers
pay, despite the pay recovery for twisters, is evidence of that differentiation.
Wage differentiation can also be seen in advertised salaries. Charts 16 and 17 plot the distribution of wage
- the words and "flexible
rates for two sets of advertised job vacancies those containing "self-employed"
hours" and those without.
These violin charts suggest that, for more flexible employment contracts, wage
distributions are materially wider. Less secure work results in a greater degree of wage differentiation.
(b) Unionisation and Collective Bargaining
A second set of structural factors potentially affecting the pay power of workers is the degree of unionisation
and collective bargaining in the labour market. Both have fallen secularly over time. Levels of unionisation
have fallen from 50% in the late 1970s to around 22% today (Chart 18). The fraction of workers covered by
collective bargaining arrangements has fallen from over 60% in 1998 to around 40% today (Chart 19).
These trends will have reduced the pressure on companies to increase wages for existing workers
("stickers"), even new entrants ("twisters") are seeing pay rises.
when As with job insecurity, this will in turn
lower workers'
have tended to pay power and increased the degree of wage differentiation within the
workplace.
Empirical research confirms those findings. Trade union membership has been found to result in a pay
premium for workers. In the UK, this premium is typically found to lie in the range 10-15%, though it may
have fallen over time.17 There is also evidence that falls in rates of unionisation and collective bargaining
have resulted in wages becoming more dispersed and differentiated across occupations and locations.18
14
Bradley (2016).
15
Gardiner (2016).
16
Gardiner (2016).
17
Bryson (2014).
18
Gregg et al (2014).
We can quantify these effects in our wage equations. In Table 1, we include the unionisation rate and
estimate over a longer sample period (1892 to 2015) to reflect the lower-frequency movements in
unionisation. This suggests unionisation is positive for pay growth and (statistically and economically)
significant. Over the sample, a 10 percentage point rise in the degree of unionisation raises wage growth by
around 25 basis points per year.
Over recent decades, unionisation rates have fallen by 30 percentage points. Using the long-run estimates,
that will have lowered wage growth by around 0.75 percentage points per year over the past 30 years, a
significant effect. Consistent with it, the sharpest falls in unionisation came in the 1970s and 1980s,
coinciding with falls in the UK labour share. Rolling regressions suggest the effects of unionisation on pay
were largest during this period.
If we look at the sectoral level, similar effects are seen. Sectors of the UK economy with higher levels of
unionisation have seen smaller falls in their labour shares (Chart 20). Over the past few decades, a sector
like administration and support activities with under 10% unionisation rates has seen its labour share decline,
while a sector like education with a unionisation rate close to 50% has seen its labour share rise.
(c) Automation
A third factor potentially affecting the pay power of workers is the degree of automation in the workplace.
The easier and cheaper it is to replace human with machine, the lower is likely to be the wage bargaining
power of workers relative to companies. Increased automation and the dawn of a Fourth Industrial
Revolution could, then, result in slower pay growth and workers receiving a smaller slice of the income pie.19
Recent research has confirmed that intuition. The IMF has found a significantly negative effect of automation
on labour's share.20 Acemoglu and Restrepo (2018) look at the influence of multi-purpose industrial robots
on pay growth across different sectors of the US economy. They find that one extra robot per thousand
workers lowers wages by 0.25-0.5%.
At 71 robots per 10,000 employees, the UK's degree of robot automation lies well below France (127), Spain
This might help explain why the UK's labour share has
(150), the US (170) and Germany (301) (Chart 21).21
fallen less markedly than in these other countries. Using the Acemoglu and Restrepo ready-reckoner, if the
UK had the same degree of industrial robot penetration as the US spread over a decade, this would lower
wage growth by around 0.4 percentage points per year.22
19
For example, Acemoglu and Restrepo (2018).
20
IMF (2017).
21
These automation measures take no account of differences in industry structure across countries.
22
We use 0.4 as the approximate mid-point of the Acemoglu and Restrepo range.
What is true across countries appears also to be true across sectors. Chart 22 plots a measure of
automation across sectors against changes in the labour share. It suggests a downward-sloping
relationship, consistent with increased automation depressing pay.
(d) Monopsony
A final factor influencing the pay power of workers is the degree of concentration in the corporate sector.
"superstar" firms, benefitting from global
There has been much recent discussion of the rise of so-called
larger a
network economies of scale and scope.23 The company's share of the product (monopoly) or labour
(monopsony) market, the greater its degree of power over customers or workers.24
Measures of industry concentration in the US (and in some other countries) have trended upwards, secularly
and significantly, over several decades. This is consistent with superstar firms gaining a greater degree of
monopolistic power over customers.25 There is also evidence linking superstar firms to rising degrees of
concentration in the labour market, consistent with a greater degree of monopsonistic power over workers.26
These shifts in industry concentration appear to have influenced pay growth. Rising concentration across
different sectors of the US economy has been found to have had a significantly negative effect on their
labour share.27 Monopsony power among US industries has been found to have had a negative effect on
wage growth in that sector, the more so when unionisation rates are low.28 And larger firms have also been
found to differentiate to a greater degree in the wages they pay their workers.29
Colleagues at the Bank, Will Abel, Silvana Tenreyro and Greg Thwaites, have recently found similar effects
in the UK.30 Higher industry concentration is associated with lower pay, the more so the less of a sector is
covered by collective bargaining. One important difference from the US is, however, that labour market
concentration has not increased anything like as much in the UK as in the US. This, too, might help explain
the relative flatness of the UK's labour share.
23
Fo