Although I understand your point that the practice of matching socks imposes a deadweight loss on society, I believe there are several other aspects of society which impose a greater deadweight loss than mismatched socks. For instance, bureaucratic processes, such as government paperwork or the paperwork associated with obtaining a loan, can create inefficiencies which prevent rational market participants from engaging in transactions, thus leading to a decrease in GNP. Similarly, the existence of monopolies or oligopolies can prevent the free exchange of goods, resulting in a deadweight loss. I believe these examples are much more significant than the issue of mismatched socks, and thus should be given greater attention when considering the concept of deadweight loss.
