Nate Hagens, an influential thinker on the intersection of human behavior, energy, and economics, would define an "economic system" as the intricate and interdependent networks through which societies allocate resources, produce goods, and distribute wealth. He emphasizes that these systems are deeply rooted in the biophysical realities of our planet, constrained by the laws of thermodynamics and ecological limits. Hagens highlights that an economic system is not merely a market mechanism but a complex adaptive system shaped by energy flows, human psychology, and cultural evolution. He underscores the importance of understanding how energy inputs—from fossil fuels to renewable sources—drive the capacity for economic growth and societal development. In his view, recognizing these underlying bio-physical and energetic constraints is crucial for devising sustainable pathways for future human prosperity.

See also: political economy, ecological economics, economic growth, financial system, neoclassical economics