During World War II, Heinrich Kraut, of the Kaiser Wilhelm Institute for Labor Physiology, studied the effect of diet on work productivity in Soviet prisoners of war under heavy forced labor in the coalmines of the Ruhr. Kraut's work illustrates an efficiency of scarcity, in which the elements of control and intervention often associated with efficiency efforts were not available. His efforts to improve productivity left unaddressed the violence and squalor amid which the prisoners lived and worked, despite his recognition that such conditions negatively affected work performance; his studies thus illustrate the primacy of National Socialist racial ideology even in labor practices crucial to war production. Kraut used technical and specialized knowledge to accommodate the brutal and inhuman labor practices of the Third Reich.