Francesco Casarella

Computer Science and Simulation for Economics

Project work on

"Salesmen in action."


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This is a model about sale-network. There's a group of person (sellers) that have to go round in a small world, consisting of a random number of supermarkets, and sell them something.


When a seller arrive on a supermarket, every agentset has its own price of reference. The price offered by the seller depends from the supplies of the supermarket (it could be hidden or not). If we've the second option, there's a discount on seller's price. Every time that a seller sell something, increase his "happy". In the rest of time each supermarket and each seller decrease respectly their own supply and happy.


Click the SETUP bottom to set up the sellers (blue colour) and the supermarkets (brown colour) with their own initial supplies. If you want to change the number of sellers, move the SELLER_NUMBER slider before using setup. The LIMIT_SUPPLY slider chooses the maximum level of initial supplies for each supermarket. The MAX_P slider chooses the reference price for sellers and supermarkets. The LIMIT_SUPPLY fixes the maximum level of supplies for each supermarket. There's an ON-OFF SHOW-INIT_SUPPLY switch. Turning off the supermarkets hide their initial supplies. The other switch CLEAN-SUPPLY give to a random number of supermarkets the chance to hide their initial supply even if the first switch's on.


The seller generally know where're positioned the supermarkets. The different for each seller is to decide how to sell goods if the supplies are hidden. The binary variable CLEAN-SUPPLY is important to give an higher level of difficult at the model. Infact every seller need to sell in a short time, because they've the problem of decreasing "happy". On the other hand, supermarkets need to buy too, but not with the same hurry (they could choose the best price). The level of happy for each seller is shown in a plot. The line colors in the plot match the number of sellers that have a level of happy over a fixed threshold.


Try different level of supermarket's supplies and try to change the number of supermarkets that have hidden supplies. What happens? We have a lowest threshold of happy for the sellers and we've a lowest level of medium price. We've a seller's variable called "time". When a seller arrives on a supermarket, he have to wait 1 seconds and in this time there's the trading. If supermarket doesn't buy the goods (in Q_S quantity), the seller go away with a worst level of happy : we've a waste of time.


The primitive PATCHES-ON lets us to give at each seller the chance to inspect the supermarket.


This model was developed by the student FRANCESCO CASARELLA in the university of TORINO, using the informatic LAB. of the economic faculty. See TERNA,P. (2008) "monopolio". SCHELLING,T. (1978) "party".