The galvanomagnetic luminescence (GML) technique is used to determine carrier lifetimes in pure and doped InSb samples near room temperature. For this purpose the theory of the GML effect is derived. The Onsager reciprocity relation between the GML effect and the photoelectromagnetic effect is also derived. (Furthermore, a related connection is obtained between the thermophotovoltaic effect and light emission by diodes.) The experimental data yield lifetimes in the range of 70 ps to 30 ns. Based on these lifetimes the quantum efficiency ηq for an excess electron-hole pair to produce a photon is determined. For intrinsic samples, ηq=3% at 20 °C and 1.5% at 70 °C. Some p-type samples have values of ηq as high as 5%. These results show that p-type doping can suppress the dominant Auger recombination mechanism in intrinsic InSb.