(Blog n°3)
Because financial exchanges are based on
relationship implying the presence of human beings, feelings, intuitions and
values, the gravity of such exchanges may be pushed into the background.
Indeed, today’s review will focus on the idea that, just like during the 1920s,
finance is a game. Of course, any game can be fun, occupy the children during a
rainy afternoon, but it is also and most importantly a way, a tool to
understand the way the human mind works. Such a knowledge would help to
understand the levers of a subject as finance, where psychological actions are
the very core of the exchanges. However, before trying to understand the
players mind, perhaps should the game be firstly analyzed.
Essentially, the core point of a game is to
find an equilibrium, a state where nothing can change. Even if the financial
game cannot end, it still can reach a balance. According to V. Pareto (1909),
such an equilibrium can only be optimal. Indeed, the players being rational
individuals, they can only adopt the most perfect situation. An optimum such as
defined by V. Pareto is a situation in which the well-being of one individual
cannot be improved without reducing the well-being of the other participants.
This kind of optimum can exist in the financial
market (if the shareholder’s wealth is considered as their well-being). Indeed,
the Pareto’s optima could be assimilated with the capital market line: an
optimal situation in which the profitability of a portfolio cannot be improved
without increasing the volatility of the portfolio. This capital market line is
a market balance, fixed by the offer and demand law, by the “invisible hand”,
so theoretically, it is a Pareto optimum (that follows Pareto’s assumptions).
However, players could be victim of bias. The
economist and mathematician J. Nash theorized such a phenomenon in 1950.
According to his theory, another equilibrium can be reached in a similar game
that the one presented by Pareto. However, this other equilibrium is not an
optimal one in the terms determined by Pareto. The most famous example of this
kind of situation is the prisoner dilemma. A fictional situation where the lack
of trust between two persons is key: because two prisoners accuse each other,
they are both condemned to a sentence that could have been reduced if they
would have remained quiet. Nevertheless, the game forced them to denounce each
other by rewarding such an act. This reward created this lack of trust.
Trust. Again, it is the core point of the whole
economic system. Trust in prices, in money, in computers are conditions for the
global financial functioning. Therefore, the actors of the market are potential
prisoners. A slight doubt can create a situation in which the well-being of the
participants is not optimized, in which the objective of an optimal shareholder
wealth is missed.
However, all of these theories assume that participants
are purely rational. This point remains controversial.