Reiner Kümmel (born 9 July 1939 in Fulda[1]) is a German physicist specialised in solid-state physics, thermodynamics and econophysics.

[4] From 1970 to 1972, he worked in Colombia at the Universidad del Valle in Cali,[2] where he helped to set up a master's programme in physics on a DAAD scholarship, which served to develop the next generation of academics.

A lively exchange developed with Wolfgang Eichhorn, who worked as an economist (and mathematician) at the Faculty of Economics at the University of Karlsruhe.

[14][15] Kümmel, and colleague Dietmar Lindenberger first fit the LINEX function using electricity as a proxy for the useful work from energy inputs.

[12] The resulting fits were able reproduce observed historical economic growth without assumptions of exogenous and unexplained technological progress.

[16] Consequently, so called technological progress in neoclassical models can be explained, in large part, as the ability of mankind to integrate increasing energy flows into the economic process and to transform it with high efficiency into useful work.

As Kümmel states "we owe a substantial part of our material wealth to energy conversion in the machines of the capital stock".