According to Philip Parker, the relationship between physics-
based physiology and macroeconomics may come to dominate
explanations of economic growth. His argument focuses on the so-
called equatorial paradox—the phenomenon that a country's
latitude explains up to 70 percent of cross-country variances in
per capita income. After introducing concepts from physics and
physiology as the building blocks of homeostatic utility, he
explains the role of homeostatic utility in economic growth.
Specifically, he shows that a country's performance is gauged
not by its absolute level of income or consumption, but by how
far it is from a homeostatic steady state governed by what he
calls physioeconomics. Countries closer to their homeostatic
steady state grow more slowly than those farther away. Parker
shows how factors such as income, aggregate savings, investment,
technology, entrepreneurship, production, and outputs per worker
are influenced by the more fundamental principles of physics and
physiology. He focuses partic