This article seems to be written with the assumption that there is always a unique equilibrium. In most interesting instances, there are many. However, a set of cognitive limitations seems to cause people to focus on models with a unique equilibrium solution (e.g. Prisoners Dilemma) rather than more interesting models (e.g. Game of Chicken, coordination games etc)
In addition, people seem like to confuse the economic meaning of rationality (optimization subject to constraints) with their fantasies of what "rational" means). They like this confusion so much that more well known cases are considered worth of a Nobel.
If you are honestly interested in understanding the role equilibria play in economics, don't overload the term. Think of an equilibrium as a prediction of where behavior tends accepting the idea that which equilibrium is selected can depend on expectations. In that regard, Karl Shell's seminal work on Sunspot Equilibria is very informative.
As for rationality, ask if the following make sense: People make choices from subsets of a vector space. They can choose between any two elements of such a vector space. Given `N` elements of such a vector space, if x1 is better than x2 and x2 is better than x3 and ... x(N-1) is better than xN, then xN is NOT better than x1. Given any element X of the choice space, one can imagine another element Y which is close to X but is better than X.
By the way, the last one, local nonsatiation, is what people tend to call "greed".
If those assumptions make sense, then you don't have much of a problem with rational choice theory.
In particular, if those assumptions make sense, you accept that demand curves are downward sloping.
In addition, people seem like to confuse the economic meaning of rationality (optimization subject to constraints) with their fantasies of what "rational" means). They like this confusion so much that more well known cases are considered worth of a Nobel.
If you are honestly interested in understanding the role equilibria play in economics, don't overload the term. Think of an equilibrium as a prediction of where behavior tends accepting the idea that which equilibrium is selected can depend on expectations. In that regard, Karl Shell's seminal work on Sunspot Equilibria is very informative.
As for rationality, ask if the following make sense: People make choices from subsets of a vector space. They can choose between any two elements of such a vector space. Given `N` elements of such a vector space, if x1 is better than x2 and x2 is better than x3 and ... x(N-1) is better than xN, then xN is NOT better than x1. Given any element X of the choice space, one can imagine another element Y which is close to X but is better than X.
By the way, the last one, local nonsatiation, is what people tend to call "greed".
If those assumptions make sense, then you don't have much of a problem with rational choice theory.
In particular, if those assumptions make sense, you accept that demand curves are downward sloping.