📈 economics

Youth Labour Market Dynamics, Human Capital, and Economic Growth: An Endogenous Growth Model

This paper presents an endogenous growth model demonstrating that long-run economic growth is determined not only by human capital accumulation through education but also critically by the efficiency with which this capital is absorbed into productive employment, as unemployment-induced skill depreciation and absorption rates significantly influence growth outcomes.

Original authors: Anupam Hazra, Akash Kumar Mukherjee

Published 2026-10-29

📖 5 min read🧠 Deep dive

CC BY 4.0

Original authors: Anupam Hazra, Akash Kumar Mukherjee

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

For decades, economists have held a simple, comforting belief about how nations become rich: if you teach your people, the economy will grow. This idea rests on the concept of human capital, which is essentially the sum of a worker's skills, knowledge, and health. Just as a factory needs machines to produce goods, an economy needs skilled people to produce value. Traditional theories suggest that investing in schools and training builds this stock of talent, which naturally flows into the workforce and drives long-term prosperity. However, this view often treats the transition from the classroom to the job as automatic, assuming that a degree or a certificate instantly becomes a productive contribution to the economy. It overlooks the messy reality of the labor market, where a skilled worker might sit idle, or where a degree might not match the available jobs.

A new theoretical study challenges this automatic assumption by looking closely at what happens to young people after they finish their education. The researchers, working within the field of endogenous growth theory—which focuses on how internal factors like education and innovation drive an economy rather than outside forces—asked a critical question: what if the skills we build are lost before they can be used? They constructed a model that treats the youth population not as a single block of potential, but as three distinct groups: those currently learning, those working, and those who are unemployed. By tracking these groups, the study reveals that the mere accumulation of skills is not enough to guarantee growth; the economy must also be able to absorb those skills into productive work.

The core of this research is a new concept the authors call the "absorption rate." Imagine a factory that produces a high-quality product but has no way to ship it to customers; the product sits in a warehouse, gathering dust, and the factory eventually stops making it. In this economic model, the "product" is the human capital gained through education, and the "warehouse" is unemployment. The study finds that when young, educated people cannot find work, their skills do not just sit idle; they actively decay. Just as a tool left in the rain will rust, a worker's knowledge and abilities diminish when they are not used. The model shows that this loss of skill, caused by the frustration and lack of practice associated with unemployment, acts as a drag on the entire economy's growth.

The researchers built a mathematical framework to test how these dynamics interact over time. They divided the total population of young people into those in school, those with jobs, and those without. They then observed how the economy performed under different conditions. The results were clear: long-term economic growth depends on two things working together. First, the economy must continue to invest in education to build new skills. Second, and equally important, the labor market must be efficient enough to hire these skilled workers quickly. If the rate of unemployment among the youth is high, the skills they learned begin to fade, and the return on the money spent on their education drops significantly. The study suggests that a country with a highly educated workforce but a poor ability to hire them will grow much slower than a country that efficiently matches its skilled workers to jobs.

One of the most striking findings is the sensitivity of growth to the "absorption rate." This rate measures how effectively the economy turns a degree or a certificate into a paycheck. The model indicates that even if a nation increases the number of students in school, if the labor market remains rigid or unable to create enough jobs, the economic benefits will be limited. In fact, the study shows that the negative impact of unemployment is not just a temporary setback; it creates a cycle where skills erode, making it even harder for those workers to find jobs later, which further slows down economic progress. The authors argue that this is why some countries with similar levels of education investment see very different economic outcomes: the difference lies in how well their labor markets function to utilize that talent.

The paper also explores the idea that the natural aging of skills and the rapid pace of technological change cause some loss of value over time, but it emphasizes that unemployment accelerates this process. When a young person is unemployed, they lose the daily practice that keeps their knowledge sharp. The study suggests that this depreciation of human capital is a direct cost to the economy, reducing the overall productivity of the workforce. Therefore, policies that focus solely on building more schools or training more workers are incomplete. To truly sustain growth, a nation must also focus on the mechanisms that connect those workers to jobs, ensuring that the skills being built are actually put to use.

Ultimately, this research shifts the conversation about economic development. It moves beyond the simple metric of how many people are educated to ask how many of those educated people are actually working. The authors conclude that the "demographic dividend"—the economic boost that comes from having a large, young population—is not automatic. It is only realized if the economy can successfully integrate that young population into productive employment. If the labor market fails to absorb these workers, the potential of the youth bulge is wasted, and the skills they possess begin to vanish. The study serves as a reminder that education and employment are not separate issues; they are two halves of a single engine that drives long-term prosperity. Without the second half, the first half cannot move the economy forward.

Technical Summary: Youth Labour Market Dynamics, Human Capital, and Economic Growth

Problem Statement
While endogenous growth theory has long established human capital accumulation as a primary driver of long-run economic growth, conventional models often treat the transition from education to productive employment as an implicit or automatic process. These frameworks typically assume that once skills are acquired through education, they immediately contribute to production. However, this assumption overlooks critical labour market frictions, particularly the phenomenon of youth unemployment. In many economies, high educational attainment coexists with persistent youth unemployment, prolonged school-to-work transitions, and skill mismatches. The existing literature largely analyzes human capital formation and labour market allocation as separate domains, failing to provide an integrated theoretical framework that explains how the efficiency of absorbing skilled youth into employment influences long-run growth. Consequently, there is a lack of understanding regarding how unemployment-induced skill depreciation and labour market absorption rates interact to determine economic performance.

Methodology
The paper develops a theoretical endogenous growth model for a closed economy to address this gap. The model integrates youth labour market dynamics directly into the production and accumulation functions.

Factors of Production: The economy utilizes physical capital ( $K$ $K$ ) and youth labour ( $N$ $N$ ). The total youth population is partitioned into three distinct states:
1. Youth engaged in education or training ( $L_e$ ).
2. Employed youth labour ( $L_p$ ).
3. Unemployed youth ( $L_u$ ).
Production Function: Output ( $Y$ ) is determined by a Cobb-Douglas production function where labour productivity depends on the stock of human capital ( $H$ ) and the quantity of employed youth labour ( $L_p$ ), rather than the total labour force.
$Y(t) = K(t)^\alpha [H(t)L_p(t)]^{1-\alpha}$
Human Capital Accumulation: The evolution of human capital ( $\dot{H}$ $\dot{H}$ ) is modeled as a function of educational participation and depreciation. Crucially, the depreciation rate ( $\delta_H$ $δ_{H}$ ) is endogenous and composed of two parts:
1. A natural rate of depreciation ( $\delta_0$ ) due to ageing and technological obsolescence.
2. An unemployment-induced depreciation rate ( $\delta_u = c_u u$ ), where $u$ is the youth unemployment rate and $c_u$ represents the marginal cost of skill loss due to unemployment.
  Thus, the accumulation equation is:
  $\dot{H}(t) = \eta e H(t) - (\delta_0 + c_u u)H(t)$
  where $\eta$ is education efficiency and $e$ is the share of youth in education.
Physical Capital: Capital accumulation follows the standard Solow formulation, driven by a constant saving rate ( $s$ ) and physical depreciation ( $\delta_K$ ).
Balanced Growth Path (BGP): The model derives the steady-state growth rate ( $g$ ) where output, capital, and human capital grow at a common rate. The resulting long-run growth equation is:
$g = \eta e - c_u u - \delta_0$
Absorption Rate (AR): The paper introduces the Absorption Rate, defined as the ratio of employed youth to the youth labour force ( $AR = L_p / LF$ ), which is mathematically linked to the unemployment rate by $u = 1 - AR$ .

Key Contributions
The paper makes three primary theoretical contributions to the growth literature:

Unified Framework: It integrates endogenous growth theory, human capital theory, and labour market allocation into a single analytical framework centered on youth labour market dynamics.
Unemployment-Induced Depreciation: It explicitly models the depreciation of human capital as a function of youth unemployment, establishing a direct channel through which labour market conditions negatively impact the stock of productive skills.
Absorption Rate as a Growth Determinant: It proposes the "Absorption Rate" (AR) as a theoretical measure of human capital–employment efficiency. This metric captures the extent to which accumulated human capital is successfully translated into productive employment, offering a mechanism to explain growth differentials among economies with similar levels of educational investment.

Results and Comparative Statics
The model yields several comparative static results regarding the determinants of long-run economic growth ( $g$ ):

Education Participation: An increase in the share of youth in education ( $e$ ) or education efficiency ( $\eta$ ) positively impacts the long-run growth rate.
Unemployment: An increase in the youth unemployment rate ( $u$ ) or the marginal cost of skill loss ( $c_u$ ) negatively impacts growth.
Absorption Rate: An increase in the Absorption Rate ( $AR$ ) leads to a positive effect on the long-run growth rate. Specifically, $\frac{\partial g}{\partial AR} = c_u > 0$ . This indicates that improving the efficiency with which human capital is absorbed into employment prevents skill decay and enhances productivity.
Natural Depreciation: The natural rate of depreciation ( $\delta_0$ ) reduces the growth rate one-for-one but acts as a level shifter rather than altering the marginal returns to education or unemployment variables.

Significance and Claims
The paper claims that its significance lies in shifting the focus of growth theory from the mere accumulation of human capital to its productive utilization. The authors argue that the economic returns to education are contingent upon the structural capacity of labour markets to absorb skilled workers.

The model demonstrates that a "demographic dividend" is not automatic; it is realized only when the transition from education to employment is efficient. If labour market frictions prevent the absorption of skilled youth, the resulting unemployment leads to skill depreciation, thereby eroding the potential growth benefits of educational investment. By introducing the Absorption Rate, the paper provides a theoretical basis for understanding why economies with similar educational attainments may exhibit divergent growth trajectories. It posits that labour market allocation is not merely a consequence of growth but an integral component of the growth process itself, where the efficiency of matching skilled workers to jobs is as critical as the investment in skills.

Technical Summary: Youth Labour Market Dynamics, Human Capital, and Economic Growth

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