Craig Holmes
ESRC Centre on Skills, Knowledge and Organisational Performance,
University of Oxford
Polarisation, mobility and segmentation in the labour market
Labour market segmentation• Labour market segmentation theory developed as a
departure from traditional models of labour supply and demand in the 1960s and 1970s
• LMS suggests it is possible to identify parts of the labour market between which mobility is severely or entirely restricted – These restrictions are related to factors other than individual
skills or abilities– Dual market: primary and secondary sector distinguished by
wages, security, prospects for promotion and training investment– Initial employment matters workers becoming ‘trapped’
Labour market segmentation• The initial literature did not find significant empirical
support.– Mayhew and Roswell (1976) looking at mobility between three
labour market segments in the UK over the past working life of employees in 1972.
– Segments were defined by occupation and status within their jobs.
– Allocation of each occupation-status pair was based on the authors' own judgment, intention of creating segments of the lowest possible mobility.
– Mobility matrices derived from this method show significant mobility between segments for many individuals.
Job polarisation in the UK• Polarisation hypothesis (Goos and Manning 2007):
– Price of computer capital has fallen since late 1970s– Computer capital replaces labour engaged in routine tasks– Non-routine tasks may be complementary to computer capital
(e.g. management, skilled professionals)– Result: growth in non-routine occupations due to changes in
demand (complementarities) and supply (displaced routine workers)
– Routine occupations found in middle of income distribution– Non-routine occupations found at top and bottom of distribution
• Managers, skilled professionals at the top• Non-routine ‘service’ occupations at the bottom e.g. hairdressers, cleaners
Polarisation and segmentation• Obvious overlap between the primary and secondary
segments and growth occupations• Individuals tend to move short distances within the
labour market in terms of job quality. Declining middling occupations reduces options for transitory upward steps to better occupations.
• Hence, a hollowed-out labour market could create two segments with limited mobility between them.
The labour market and segmentation• Jobs defined by occupation, industry and skill:
Industries
Occupational groups increasing in quality
Levels of skill or expertise within each industry-occupation
The labour market and segmentation• Example 1: craft union model or occupational labour
markets Industries
Occupational groups
Primary segment
Secondary segment
The labour market and segmentation• Example 2: internal labour markets
Industries
Occupational groups
Primary segment
Secondary segment
The labour market and segmentation• Example 3: polarisation
Industries
Occupational groups
Primary segment
Secondary segment
Middling occupations
The labour market and segmentation• A hollowed-out labour market has
– Fewer middle jobs for low wage workers to move into– Increasing competition for those that remain. – Significant upward mobility may either be slower, or require
much more difficult and sizeable leaps.
• Before embarking on a study of mobility using longitudinal analysis, it is important to understand the ways the polarisation phenomena has or has not manifested within a dataset that can be used for analysing working life mobility
Job polarisation in the UK: an assessment• Holmes, (2010), SKOPE research paper No. 90• Looks at single cohort from National Child Development
Study between 1981 (aged 23) and 2004 (aged 46).• Replicates the Goos and Manning methodology for our
NCDS dataset– Finds growth in high wage and low wage occupations, decline in
mid-range occupations, proxied by 1981 wage– Evidence of routinisation driven employment changes
Job polarisation in the UK: an assessment• However, wage distributions exhibit little evidence of
polarisation– Most jobs still fall in the middle of wage distribution– How can these two observations be reconciled?
• Existing evidence relies on a strong assumption that wage structures have remained constant over the past three decades– Changing wage structures, due to the associated changes in
supply and demand of different workers, may have led to a new type of middling occupation
• Change in employment share of wage deciles. • Initially highest and lowest paid occupations grew more
than the middle earning occupations
Job polarisation in the UK: an assessment
Job polarisation in the UK: an assessment• Resulting wage distributions are important• Absent of other effects, a polarising labour force should
be observed as in the diagram below
log wage
cumulative probability
0
1 initial distribution
polarising distribution
• Changing distributions from NCDS cohort (hourly and weekly, full-time workers):
Job polarisation in the UK: an assessment
• Econometric methods for analysing changes accurately• Descriptive method (see Holmes, 2010) – change in
employment at each (log) wage percentile• Polarisation illustrative example:
Job polarisation in the UK: an assessment
Further research• This suggests polarisation may not be as clear-cut a
mechanism for creating labour market segmentation• However, still suggests several issues for further mobility
analysis– Destinations of displaced routine occupation workers
• Are they able to move upwards?• Difference between occupational and wage mobility
– Experience of new entrants compared to existing workers • Are new entrants more polarised? • Do they experience different patterns of occupational and wage mobility
– Role of skills in both cases
Further research• Destination of displaced routine workers
– Model: four occupational categories (professional, managerial, routine and service)
– Separate out transitions from routine occupations caused by routinisation from those caused by career advancement
– Similarly for transitions between routine and service occupations– Empirical strategy:
• Define four occupational categories (SOC, SEG)• Calculate transition probabilities in NCDS (1981 – 2004)• Apply to larger sample of 23 year olds in 1981 (e.g. LFS) and compare to a
counterfactual occupational structure (e.g. 46 year olds in LFS 1981)
Further research• Destination of displaced routine workers
– Initial results:
• Probability of transition to professional depends on having a degree, rather than starting occupation
• Need to breakdown upward movers by upskilled and non-upskilled
Initial structure, 1981, 23 year
olds
Pre-routinised structure, 46 year
olds
Post-routinised structure, 46 years olds
Professional 8.4% 9.5% 13.2%
Managerial 10.1% 12.6% 25.6%
Routine 69.3% 66.6% 41.1%
Service 12.2% 11.3% 20.1%
Further research• Different experiences of later cohorts
– Autor and Dorn (2009) – declining occupations are getting “older”
– Continue using cohort approach - make use of later cohort study (1970 British Cohort Study) for comparison
– Differences at entry – more polarised as older workers hold on to positions in declining occupations. New entrants driving cross sectional polarisation?
– Different mobility opportunities compared to NCDS cohort?