Comparison of three behavior pattern models

The fifth chapter is about mannequins.

There are three human models:

(1) rational behavior model: people are rational and will adopt the optimal strategy for their own goals;

(2) Behavior model: It is assumed that all behaviors are rational, but there will be deviations, that is, the degree of rationality is slightly lower;

(3) Rule-based model: Assuming that people follow certain rules, these rules can be fixed or adaptive.

So, what kind of behavior will people have? Whether it is established rules, optimal strategies or behavior patterns, it is simply explained by examples in the course.

This is an example of market exchange, just for exchange.

There are buyers and sellers in the market.

The buyer wants to buy goods, and the bidding range is from 0 yuan to 100 yuan;

The seller wants to sell the goods, and the selling price ranges from 50 yuan to 150 yuan;

First of all, assume that both buyers and sellers are rational.

In principle, the buyer's asking price will be lower than the acceptable real price, because he wants to take advantage; The price offered by the seller is likely to be slightly higher than the real price acceptable to the buyer. The extent to which the prices offered by buyers and sellers deviate from the true value depends on the distribution of acceptable prices between buyers and sellers. Assuming that buyers and sellers continue to bid until the market is clear, that is, finding a certain price makes the total amount of goods that people are willing to sell exactly equal to the total amount purchased. The principle of this mechanism is: each buyer announces a price they are willing to buy; Each seller also announces a price they are willing to sell, and then we take an intermediate price from it, so that an equal number of buyers and sellers can make a deal. Because people are rational, buyers who can buy things should actually bid between 50- 100, and sellers who sell things can only bid between 50- 100. In the end, we will get a price of around 75 to balance the market.

Thirdly, suppose that people's rationality is biased, and they can't adopt the optimal strategy on how to bid, and may adopt some centralized bidding methods. For example, people tend to bid 50, 60 and 70, focusing on some integers, but even so, the final price will not be too far from 75.

Finally, in the case of rules-based, such as a simple rule model called "zero intelligent trader", the rules select some random numbers that are lower than the highest price that the buyer is willing to pay; The seller chooses some random numbers higher than the lowest price he is willing to sell. Using these zero-intelligence traders to analyze this market will eventually get a price close to 75.

Finally, comparing rational behavior, deviation and simple rules, we can see that sometimes the difference between the results is very small, and the results do not seem to change with the behavior; But sometimes there are obvious differences, and it is necessary to consider which of the three modes is more suitable according to the situation.