I was talking with a friend about that 1% of the population owns like 99% of the wealth. My arguments were that through the history, there were always very rich people owning large wealth, and many poor people, and the current situation might not be so different than, let's say, 1000 years ago.
The question: are there any studies about the variation of this proportion between the rich and poor in time? In different societies? Different species? Is this value a constant? For example, in every society, the rapport between rich and poor is 1:99? Do such sociological constant even exists?
Innocent disclaimer: is this a history question or a sociology question?
No. In fact, most modern day countries do not even come close to such an unequal distribution of wealth. 1% owning 99% of the wealth would create a Gini index of about .99 if I am not mistaken, much higher than anything we see today (the US, for example, only has a Gini index hovering around .45, and that is already considered very high).
But it also depends on your definition of wealth. If you're just talking about "money" as in cash, it's very difficult to say, as large chunks of human history many societies didn't really have a well established currency system. Even more problematic is money is incredibly difficult to keep track of, especially with credit markets and banks. You'd probably get a better picture if you simply look at income inequality on a year to year basis, but that also creates problems such as tracking individuals over the course of years. And these problems are assuming access to modern data. Imagine how difficult this would be without good records and data sources.
However, if you are talking about wealth as in material ownership (ie land, capital, etc), then this level of inequality is certainly plausible during some periods of human history. Feudal Europe, for example. Or Dynastic China.
Many studies have been done about this subject, depending on how academic you want to get. Sociologically, wealth distribution has always been a poor indicator on how well of society is, since there are countless factors that can distort it (public programs, for instance. Or temporary unemployment. Or different stages of an individual's life. Etc etc etc etc).
As for your innocent disclaimer, in many ways history and sociology go hand in hand. I simply answered it using mostly Economics. But all three are basically different types of social sciences.