The main concern of mathematical economics is to express economic
theory in mathematical form (equations) without regard to measurability or
empirical verification of the theory. Econometrics, as noted previously, is
mainly interested in the empirical verification of economic theory. As we
shall see, the econometrician often uses the mathematical equations proposed
by the mathematical economist but puts these equations in such a
form that they lend themselves to empirical testing. And this conversion of
mathematical into econometric equations requires a great deal of ingenuity
and practical skill.