Macroeconomics treats capital as a cumulative stock.

Capital persists through time, can be inherited, and therefore appears in macroeconomic accounting as a stock variable.

But there is a curious asymmetry.

Human lifetime also accumulates historically: humanity continuously adds lived time across generations. Yet cumulative lifetime never appears as a macroeconomic stock.

Instead it only enters macro models as a flow (labor supply) or as a demographic constraint.

One possible explanation is institutional rather than physical.

For a variable to qualify as a macroeconomic stock it must satisfy two conditions:

1. Detachment from biological identity 2. Institutional continuity across generations

Capital satisfies both conditions. Lifetime does not.

If this reasoning is correct, macroeconomic accounting may structurally privilege capital accumulation.

Curious how economists or system designers here think about this asymmetry.

HN note: the SSRN page is still being processed and temporarily shows the standard “under review” placeholder.

The working preprint version is available here:

https://doi.org/10.5281/zenodo.18912296

The paper explores a structural asymmetry in macroeconomic accounting:

Capital accumulates and appears as a stock variable.

Human lifetime accumulates historically as well, yet it never qualifies as a macroeconomic stock and only enters models as a flow or demographic constraint.

The argument is that stock variables require two institutional properties: (1) detachment from biological identity (2) continuity across generations.

Capital satisfies both. Lifetime does not.

Curious how economists or system designers here think about this constraint.