This could suggest that paternal direct investments may not be substitutable by stepfather investments for children's socio-emotional development.
Future profits on biotech copies will largely depend on the FDA's rules for approval and whether the drugs will be truly generic or substitutable.
With respect to the supplier's optimal effort level, if the supplier's effort level and his product quality are substitutable, then his second-best effort level will be larger than the first-best one, while in the case of complement, it is smaller than the first-best level.
Therefore, the products 1 and 3 and also the products 2 and 4 will be transacted in the market as the substitutable products.
If one of the items is out of stock then its demand will be fulfilled by the second item and if any demand is not met by substitutable item it will be completely lost.
Nonetheless, this does not mean that gas pricing cannot track oil prices, for to the extent that they are substitutable; the price of one will definitely have the effect on the price of another.
Hence, by construction there will always be at least one of the other factors that is substitutable with energy.
A commodity is substitutable.
It also implies that they are substitutable.
