next up previous
Next: Heterogeneous Simulations Up: GTMY, and DF Previous: GTMY, and DF

Homogeneous Simulations

 

Here, we augment our previous work (see [9]) on simulations of 2 pricebots of matching types by assuming the uniformly distributed buyer valuations introduced in Section 3. If we consider 2 GT pricebots, simulations verify that the cumulative distribution of prices closely resembles the derived F(p), to within statistical error. The time-averaged profits for each seller were 0.0319, nearly the theoretical value of 0.03125. When 2 pricebots use the myoptimal pricing strategy, cyclical price wars result (see [9]). The myoptimal sellers' expected profits averaged over one price-war cycle are given by tex2html_wrap_inline1047 , which is equal to 0.0893. Simulation results closely match this theoretical value with an average profit per time step for MYs of 0.0892, nearly thrice the average profit obtained via the game-theoretic pricing strategy.

In related work (see [9]), assuming all buyer valuations to be equal, the behavior of DF pricebots tended towards what is in effect a collusive state in which all prices approached the monopolistic price. In this study, 2 DF pricebots once again track one another closely; in doing so they accumulate greater profits than either 2 myoptimal or 2 game-theoretic pricebots. The effect of uniformly distributed buyer valuations is nonetheless apparent in substantial fluctuations in price, ranging from approximately 0.15 to 0.55 -- the upper bound of which is above the monopolistic price tex2html_wrap_inline1049 -- rather than remain in the neighborhood of the monopolistic price. Specifically, DF pricebots achieved time-averaged profits of 0.1127.



kephart
Tue Sep 28 21:57:17 EDT 1999