Depreciation of Specific Human Capital

In the AI Story

A senior software engineer commands a salary of two hundred thousand dollars or more, not because her time is intrinsically worth that amount, but because her accumulated expertise — the debugging intuition, the architectural judgment, the capacity to navigate complex codebases built up over years — is scarce. Other people want what she can do and cannot easily do it themselves. The scarcity creates a premium. The premium justifies the investment she made. When AI tools can produce competent code in seconds, the scarcity of competent code production evaporates. The premium disappears. Her human capital, measured by its market return, depreciates. Not because her knowledge has become less real. Because it has become less scarce.

Becker's model typically treats depreciation as a continuous process — a slow erosion over time, like the physical depreciation of a machine. But AI-driven depreciation is discontinuous. It arrives as a step function: one month the skill is valuable, the next month a tool can replicate it. The senior engineer does not watch her expertise slowly become less relevant over years. She watches it become less relevant over weeks, as Claude Code ships an update that handles the class of problems she spent a decade learning to solve.

The step-function character makes rational adjustment extraordinarily difficult. Becker's model assumes agents can observe the change in returns and adjust their investment. But when change arrives as discontinuity, observation and adjustment collapse into the same moment. There is no time to retrain, no period of gradual adaptation, no long curve of declining returns providing advance warning.

AI depreciates specific capital and simultaneously accelerates the rate at which any new specific capital will itself be depreciated. The rational agent faces a moving target. She must invest in new capital whose value is uncertain, knowing the same technology that destroyed her previous investment may destroy the new one before it generates a return.

Origin

The concept of capital depreciation has been central to economics since the nineteenth century, but Becker's application of depreciation analysis to human capital — complete with maintenance requirements, obsolescence schedules, and the distinction between specific and general forms — transformed how economists understand the dynamics of skill over a career. The framework generated predictions about retraining investments, retirement timing, and wage profiles that subsequent empirical work has largely confirmed.

Key Ideas

Scarcity, not correctness, determines value. Knowledge that remains accurate but ceases to be scarce loses its market return regardless of its continued truth.

Step-function depreciation. AI produces discontinuous rather than continuous capital loss, compressing the adjustment window from years to weeks.

The accelerating trajectory. Each AI capability update not only depreciates existing specific capital but reduces the expected lifespan of replacement capital, undermining the rational investment calculus.

The rational response. Under accelerating obsolescence, rational agents reduce their overall investment in specific capital, producing a society that builds less deep expertise and loses the foundation on which valuable generalism rests.