Herman Daly (1938-2022) was an ecological economist and senior economist at the World Bank (1988-1994) whose work on steady-state economics, natural capital, and the critique of GDP growth as a welfare measure made him Donella Meadows's most important intellectual ally outside the system dynamics tradition.
Daly's central contribution was the steady-state economy — the argument that perpetual economic growth on a finite planet is physically impossible and ecologically destructive. His books Steady-State Economics (1977) and For the Common Good (1989, with theologian John Cobb) developed the economic theory that gave analytical grounding to the concerns raised by limits-to-growth-1972. Where Meadows approached planetary limits through stocks-and-flows modeling and exponential-growth analysis, Daly approached them through economic theory and thermodynamics.
The convergence between Meadows's systems thinking and Daly's ecological economics was deep: both argued that overshoot-and-collapse was the likely outcome of business-as-usual trajectories, both advocated for sustainability-indicators that went beyond GDP, and both operated outside the mainstream of their respective disciplines. Daly's participation in the balaton-group network placed him within the international sustainability community that Meadows convened — a community that represented the applied social science complement to the systems modeling work.
Meadows's indicators-of-sustainability-1998 work, produced through the sustainability-institute and balaton-group networks, drew directly on the tradition of alternative indicator development that Daly's work had made intellectually respectable. The question "what should we measure?" — which Meadows applied in her state-of-the-village-report as well — was one Daly had been pressing in economic terms for decades.
Daly's concept of strong sustainability — maintaining natural capital stock, not just its monetary equivalent — resonates with Meadows's resilience emphasis and her argument in thinking-in-systems-2008 that resilience is systematically undervalued relative to productive efficiency. Both thinkers were arguing against the same tendency to optimize for throughput while ignoring the structural conditions that make throughput possible.
The Daly-Meadows intellectual convergence also reflects a generational phenomenon: both were among the first generation of academically trained scholars to take the ecological critique of industrial growth seriously as a scientific rather than merely political question, using disciplinary tools (system dynamics modeling, welfare economics) to make arguments that ecological activists had made on normative grounds alone.