Relative growth of employment in high-skilled and well-paid jobs (such as management and technical positions) and low-skilled and low-paid jobs (such as catering and cleaning services) amid the concurrent decline in middle-skill jobs (such as clerical, construction, manufacturing, and retail trade).
Source
Based on Federal Reserve Bank of Boston, 2021.
The decline in middle-skill employment is typically attributed to the rising automation of work, but other factors (e.g. labour market institutions, globalisation, quality of labour supply) may be drivers of job polarisation.