Answer and explanation:
In order to achieve a more detailed explanation, I am going to slipt the answer in two parts: one about the economy and the other one about the culture.
The changes in the economy of the U.S, as a result of credit expansion, consumerism and financial speculation set up the appeareance of a stablished mixed economy. This kind of economy is the type that looks our for markets help in order to allocate resources, but at the same time the State intervenes so as to regulate its function.
On the other hand, the changes in the culture of the US, regarding the economical changes, made the society to be a very material one. Values morphed into very superficial ones, and I guess that's the dark side to a nice economic growth.
