There is actually a lot more turnover of wealth than in the past and most of the richest people in the world are self-made (albeit most were not exactly from humble beginnings).
> Over the past 30 years, the origin of the wealth of the richest people in the United States has shifted away from old, inherited money. Our new metric, the self-made scores developed for the Forbes 400, shows that increasingly we find self-made billionaires among the ranks of the richest people in the country. This has accompanied the incredible increase in wealth of the members of the Forbes 400, which has jumped 1,832% times since 1984, when the total net worth of our list was $125 billion, compared with $2.29 trillion today [0]
> Over the past 30 years, the origin of the wealth of the richest people in the United States has shifted away from old, inherited money. Our new metric, the self-made scores developed for the Forbes 400, shows that increasingly we find self-made billionaires among the ranks of the richest people in the country. This has accompanied the incredible increase in wealth of the members of the Forbes 400, which has jumped 1,832% times since 1984, when the total net worth of our list was $125 billion, compared with $2.29 trillion today [0]
[0] http://www.forbes.com/sites/afontevecchia/2014/10/03/there-a...