The difference between the Ricardian model oftrade and the immobile factor model is that: O Ricardo assumed one factor of production while the immobile factor model assumed two factors of production. labor and capital. 0 Ricardo considered the countrya s workforce as an endogenous variable. while the immobile factor model considered labor supply as exogenous. O Ricardo assumed a barter economy while the immobile factor model introduced money into the system. 0 Ricardo assumed labor was immobile between industries, while the immobile factor model considered labor to be immobile only between countries. 0 Ricardo assumed labor employed in each sector to be endogenous. but the immobile factor model assumed labor employed in each sector to be exogenous