Furthermore if the labor theory of value held up then capital would not relate back to the same long term rate of return, as some capital would be employed in more labor intensive areas. This would mean that different forms of capital would have different intrinsic rates of return, something that immediately put Marxist economics at a disadvantage to the neoclassical, Austrian and Keynesian schools. This was a problem that dogged Marxist economists.
Originally put forward by the Austrian School economist Eugen von Boehm-Bawerk:
Either products do actually exchange in the long run in proportion to the labour attaching to them—in which case an equalisation of the gains of capital is impossible; or there is an equalisation of the gains of capital—in which case it is impossible that products should continue to exchange in proportion to the labour attaching to them.