Recently, there was an electoral process in the USA. At the first glance, it seems odd that the president of the most powerful country of the world is not elected by a proportional method of distributing the real votes among the electoral votes. Thinking about it, I find the conclusion (of course, well known yet) that the electoral law must have a strong influence in the complexity of a country and its economy.
But I want to go farther and try to analyze if the winner takes it all method is more commonsense than the proportional one.
Aristotle defined democracy as a government that treats as equal what is equal and as different what is different. The winner takes it all method is based on considering than people has similar needs if they live near. Of course our neighbors’ needs can be different from ours, but in terms of government actions this can be true. Executive power does not make decisions affecting single people; this is a role of the judicial one. Central government makes decisions that affect groups of people, for instance, a highway can be done in a region or in another different one. As administrative investment decisions are geographical, we can consider that looking at the big picture regions can be considered as homogeneous.
Of course, the size of the constituency is what will guarantee this homogeneity. Namely, in mathematical language, the limit of a representative democracy with a winner takes it all method when the size of the constituency tends to zero is the natural democracy (one man, one vote).
However, in a proportional scheme this mathematical law has not this physical sense. The proportional scheme is based on the principle that all parties are proportionally represented, but parties have not a physical existence as geographical restrictions and funding decisions and government managing actions must have an effect on the physical structure of the country.
A system of parties with a proportional electoral law will never work as a democracy because only preserve the principle that different things must be considered different but does not preserve the principle that equal things must be considered equal.
A proportional scheme tends to provide a government that only considers the needs of the party in the government that is a virtual structure on the real structure of the people that defines the country. The government of a homogeneous group of people is far from democracy as it was invented in order to avoid that a homogeneous group of people could govern a country without considering the needs of the other groups. In other words, in a proportional scheme MPs represent nobody (with a physical sense), they can be only acting following the guidelines of their parties (with a virtual sense).
If you think that this reasoning is incorrect, probably you have not any knowledge about physics or engineering. There is not any difference between a winner takes it all scheme and a Finite Element Analysis (FEA). When we need to model the behavior of a mechanical device, we can divide it in single pieces that we consider homogeneous and analyze how they interact under external forces. The goodness of the model depends strongly on the mesh. If the mesh has not been done following a physical sense the results tend to be extremely erroneous.
The problem with an erroneous representation system is the large amount of complexity that provides to the whole system.
If the initial hypothesis considering that decisions of the central government have influence mainly in geographical zones is valid, a winner takes it all model with a single member of parliament every constituency has physical sense depending on its size and the structure, any other kind of model would introduce complexity in the system only. Of course, this hypothesis can be discussed as many government decisions are not related to local infrastructure investments.