Age-Coded Job Advertisements Inflate Labour Shortages in African Economies: Machine-Learning Evidence from a Seven-Country Study

Purpose: This study interrogates the paradox of employer-reported “labour shortages” in labour-abundant African economies. It advances the claim that shortage signals are partly institutional outputs: they arise when screening rules narrow the effective labour pool, rather than reflecting exogenous skill scarcity. Design/methodology/approach: Drawing on labour market segmentation, information economics, and critical institutionalism, we analyse 10,432 job advertisements scraped monthly (January 2024–June 2025) from leading portals in seven Anglophone African countries. A rigorously validated support-vector-machine classifier distinguishes explicit numeric age ceilings from implicit youth-coded cues to construct an Age-Coded Hiring Index (ACHI). We triangulate ACHI with employer-reported workforce-constraint indicators from the World Bank Enterprise Surveys and labour-underutilisation (LU4) from ILOSTAT, estimating fixed-effects and interaction models to test whether age-coded screening predicts shortage complaints most strongly where latent labour supply is greatest. Findings: Age-coded screening is pervasive in vacancy texts: approximately 15–20% of postings impose numeric age caps and a much larger share deploys implicit youth signals. Higher ACHI is robustly associated with stronger shortage complaints net of underutilisation and macro controls, and the relationship steepens under high labour slack, consistent with an institutional mechanism in which screening rules convert latent labour supply into perceived scarcity. Originality/value: Conceptually, the paper reframes “shortage” indicators as partially endogenous to screening rules and to employers’ definition of “suitability,” rather than treating them as market facts. Empirically, it introduces a replicable NLP-based measure of exclusionary screening from vacancy text, enabling cross-country tests of institutional scarcity dynamics in low- and middle-income contexts. Practical implications: The results imply that diagnostic and policy responses to “shortages” should not presume supply failure alone; they should also examine how recruitment criteria restrict the recognised labour pool and thereby shape shortage measurement itself.

labour shortages; institutional ageism

1. Age Discrimination Info (ADI). (2023, July 19). Age discrimination in Nigeria: Ban on age limits in recruitment? Age Discrimination Info. https://www.agediscrimination.info/news/2023/7/19/age-discrimination-in-nigeria-ban-on-age-limits-in-recruitment [Google Scholar] [Crossref]

2. Akerlof, G. A. (1970). The market for “lemons”: Quality uncertainty and the market mechanism. Quarterly Journal of Economics, 84(3), 488–500. https://doi.org/10.2307/1879431 [Google Scholar] [Crossref]

3. Association of Personnel Service Organisations (APSO). (2023). Discrimination and Job Advertising (Industry News). Retrieved from https://apso.org.za/industry-news/77-discrimination-and-job-advertising [Google Scholar] [Crossref]

4. BrighterMonday Kenya. (2024). Jobs bulletin, volume 1: Online labour market insights January 2024 – June 2024. BrighterMonday. https://www.brightermonday.co.ke/research [Google Scholar] [Crossref]

5. Burn, I., Button, P., Pounds, A., & Von Wachter, T. (2022). Can employers detect age discrimination through job ads? Journal of Human Resources, 57(4), 1243–1278. https://doi.org/10.3368/jhr.57.4.0418-9446R2 [Google Scholar] [Crossref]

6. Cappelli, P. H. (2015). Skill gaps, skill shortages, and skill mismatches: Evidence and arguments for the United States. ILR Review, 68(2), 251–290. https://doi.org/10.1177/0019793914564961 [Google Scholar] [Crossref]

7. Careers24. (2025). Annual labour market overview 2024/25. Media24. https://www.careers24.com [Google Scholar] [Crossref]

8. Cleaver, F. (2012). Development Through Bricolage: Rethinking Institutions for Natural Resource Management (1st ed.). Routledge. https://doi.org/10.4324/9781315094915 [Google Scholar] [Crossref]

9. Cleaver, F., & Koning, J.D. (2015). Furthering critical institutionalism. The International Journal of the Commons, 9, 1-18. https://www.semanticscholar.org/reader/86d350b1cf468167b852bd15f7523bbef7ad916b [Google Scholar] [Crossref]

10. Houston, D., & Lindsay, C. (2025). Measuring labour market slack: Reconceptualising underutilisation beyond unemployment. Journal of Labour Market Research, 59(1), 1–18. https://doi.org/10.1186/s12651-025-00396-z [Google Scholar] [Crossref]

11. Human Rights Watch. (2021, March 19). New WHO report calls out global impacts of ageism. https://www.hrw.org/news/2021/03/19/new-who-report-calls-out-global-impacts-ageism [Google Scholar] [Crossref]

12. International Labour Organization (ILO). (2020). Skills and jobs mismatches in Africa: Report on enterprise skills survey findings (ILO Publication No. WCMS_736678). International Labour Office. https://www.ilo.org/sites/default/files/wcmsp5/groups/public/@ed_emp/@emp_ent/documents/genericdocument/wcms_736678.pdf#:~:text=et%20al,In%20Tunisia . [Google Scholar] [Crossref]

13. International Labour Organization. (2016, April 14). Labour underutilization. https://www.ilo.org/resource/labour-underutilization [Google Scholar] [Crossref]

14. Jobberman Nigeria. (2025). Jobs bulletin, volume 1: Online labour market trends January 2024 – June 2025. Jobberman Research Unit. https://www.jobberman.com/research [Google Scholar] [Crossref]

15. Kureková, L. M., Beblavý, M., & Thum-Thysen, A. (2015). Using online vacancies and web surveys to analyse the labour market: A methodological inquiry. IZA Journal of Labor Economics, 4(1), 18. https://doi.org/10.1186/s40172-015-0034-4 [Google Scholar] [Crossref]

16. Lahey, J. N. (2008). Age, women, and hiring: An experimental study. Journal of Human Resources, 43(1), 30–56. https://doi.org/10.3368/jhr.43.1.30 [Google Scholar] [Crossref]

17. Leontaridi, M. R. (1998). Segmented labour markets: Theory and evidence. Journal of Economic Surveys, 12(1), 63–101. https://doi.org/10.1111/1467-6419.00052 [Google Scholar] [Crossref]

18. Mathew, E. (2024). Beyond unemployment: Measuring labour underutilisation in developing economies. International Labour Review, 163(1), 3–29. https://doi.org/10.1111/ilr.12403 [Google Scholar] [Crossref]

19. MyJobMag. (2025). 2025 Nigeria job search report. https://www.myjobmag.com/blog/2025-myjobmag-job-search-report-2 [Google Scholar] [Crossref]

20. National Institute of Statistics of Rwanda (NISR). (2025, January 27). Labour Force Survey (Q4, 2024). https://alpha.statistics.gov.rw/data-sources/surveys/Labour-Force-Survey/labour-force-survey-2024/labour-force-survey-q4-2024 [Google Scholar] [Crossref]

21. Neumark, D., Burn, I., & Button, P. (2019). Is it harder for older workers to find jobs? New and improved evidence from a field experiment. Journal of Political Economy, 127(2), 922–970. https://doi.org/10.1086/701029 [Google Scholar] [Crossref]

22. Nigeria National Assembly. (2023). Prohibition of Age Restrictions in Employment Bill, 2023 (HB 2391). Abuja: Federal Republic of Nigeria. [Google Scholar] [Crossref]

23. Nkosi, N. (2024, Aug 20). Civic movement calls on government to scrap hiring age limit for police and defence forces. IOL News – The Star. https://www.iol.co.za/the-star/news/2024-08-20-civic-movement-calls-on-government-to-scrap-hiring-age-limit-for-police-and-defence-forces [Google Scholar] [Crossref]

24. Pejić-Bach, M., Bertoncel, T., Meško, M., & Krstić, Ž. (2020). Text mining of job advertisements: A systematic literature review. Economic Research-Ekonomska Istraživanja, 33(1), 1189–1206. https://doi.org/10.1080/1331677X.2020.1763829 [Google Scholar] [Crossref]

25. Spence, M. (1973). Job market signaling. Quarterly Journal of Economics, 87(3), 355–374. https://doi.org/10.2307/1882010 [Google Scholar] [Crossref]

26. Statistics South Africa (SSA). (2025, November 11). Quarterly labour force survey: Quarter 3: 2025 (Statistical release P0211). https://www.statssa.gov.za/publications/P0211/P02113rdQuarter2025.pdf [Google Scholar] [Crossref]

27. Sustainability Directory. (n.d.). Critical institutionalism theory. Sustainability Directory. https://esg.sustainability-directory.com/area/critical-institutionalism-theory/ [Google Scholar] [Crossref]

28. The World Bank, UNESCO, & International Labour Organization. (2023). Building better formal TVET systems: Principles and practice in low- and middle-income countries. https://doi.org/10.1596/978-92-2-039357-4 [Google Scholar] [Crossref]

29. Tsvetkova, A., D’Amico, E., Lembcke, A., Knutsson, P., & Vermeulen, W. (2024). How well do online job postings match national sources in large English speaking countries? Benchmarking Lightcast data against statistical sources across regions, sectors and occupations (OECD Local Economic and Employment Development (LEED) Papers No. 2024/01). OECD Publishing. https://doi.org/10.1787/c17cae09-en [Google Scholar] [Crossref]

30. World Bank. (2025). World Development Indicators 2025 [Data set]. https://data.worldbank.org [Google Scholar] [Crossref]

31. World Bank Enterprise Surveys. (2023). Enterprise Surveys: Indicator descriptions. https://documents.worldbank.org/en/publication/documents-reports/documentdetail/099033123044099859/p17884904bb32e06f0ad4900dd85b5795f6 [Google Scholar] [Crossref]

32. World Bank. (2020). Enterprise Surveys – Indicator: Inadequately educated workforce (% firms). World Bank Enterprise Survey Data. [Data excerpt indicating ~33% of firms in sub-Saharan Africa cite skills as major constraint] https://www.ilo.org/sites/default/files/wcmsp5/groups/public/@ed_emp/@emp_ent/documents/genericdocument/wcms_736678.pdf#:~:text=et%20al,In%20Tunisia [Google Scholar] [Crossref]

33. World Bank. (2019). Improving higher education performance in Kenya: A policy report (Report No. AUS0000379). World Bank. https://documents.worldbank.org/curated/en/831821566966279688/pdf/Improving-Higher-Education-Performance-in-Kenya-A-Policy-Report.pdf [Google Scholar] [Crossref]

34. World Economic Forum. (2017, May 3). Close skills gaps to prepare Africa’s workforce for tomorrow’s jobs (Press release launching The Future of Jobs and Skills in Africa). https://www.weforum.org/press/2017/05/close-skills-gaps-to-prepare-africa-s-workforce-for-tomorrow-s-jobs/ [Google Scholar] [Crossref]

35. World Health Organization. (2021, March 18). Kicking off a global conversation about ageism: launch of the first UN Global report on ageism (Event page). https://www.who.int/news-room/events/detail/2021/03/18/default-calendar/kicking-off-a-global-conversation-about-ageism [Google Scholar] [Crossref]

36. World Health Organization (WHO). (2021). Global report on ageism. World Health Organization. Available at: https://www.who.int/publications/i/item/9789240016866 (accessed March 18, 2021) [Google Scholar] [Crossref]

• Is Strike Relevant in the Modern Era? Evidence from Indian Manufacturing, IT/Ites, FMCG, Electronics and Emerging Sectors
• A Qualitative Exploration of Work-Life Balance Among Private Universities Lecturers in Klang Valley
• Leadership Styles and Employee Motivation: Examining the Impact on Job Satisfaction and Turnover
• Human Resource Management, Organizational Culture, and Good Governance Practices: A Structural Equation Model on Service Orientation among Government-Owned and Controlled Corporation in Davao Region
• Cost of Silence: Exploring the Impact of Organisational Silence on Employee Engagement