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MY Pricing Strategy

Fig. 2(a) illustrates the cyclical price wars that typically occur when all 5 sellers use the myoptimal pricing strategy. Regardless of the initial value of the price vector, a pattern quickly emerges in which prices are positioned near the monopolistic price v = 1, followed by a long episode during which the sellers successively undercut one another by tex2html_wrap_inline720 . During this latter phase, no two prices differ by more than tex2html_wrap_inline914 , and the prices fall linearly with time. Eventually, when the lowest-priced seller is within tex2html_wrap_inline720 above the value tex2html_wrap_inline918 , the next seller finds it unprofitable to undercut, and instead resets its price to v = 1. The other sellers follow suit, until all but the lowest-priced seller are charging v = 1. At this point, the lowest-priced seller finds that it can maintain its market share but increase its profit dramatically -- from tex2html_wrap_inline924 to tex2html_wrap_inline926 -- by raising its price to tex2html_wrap_inline928 . No sooner than the lowest-priced seller raises its price does the next seller who resets its price undercut, thereby igniting the next cycle of the price war.

Fig. 3(a) shows the sellers' profits averaged during the intervals between successive resetting of prices. The upper curve represents a linear decrease in the average profit attained by the lowest-priced seller as price decreases, whichever seller that happens to be. The lower curve represents the average profit attained by sellers that are not currently the lowest-priced; near the end of the cycle they suffer from both low market share and low margin. The expected average profit can be computed by averaging the profit given by Eqs. 7 and 8 over one price-war cycle: tex2html_wrap_inline930 , which yields tex2html_wrap_inline932 in this instance. The simulation results match this closely: the average profit per time step is 0.0515, which is just over twice the average profit obtained via the game-theoretic pricing strategy.

Since prices fluctuate over time, it is of interest to compute the probability distribution of prices. Fig. 4(a) depicts the cumulative distribution function for myoptimal pricing. This measured cumulative density function has exactly the same endpoints tex2html_wrap_inline918 and v = 1 as those of the mixed strategy equilibrium, but the linear shape between those endpoints (which reflects the linear price war) is quite different from what is displayed in Fig. 1(a).


next up previous
Next: DF Pricing Strategy Up: Price and Profit Dynamics Previous: GT Pricing Strategy

kephart
Wed Apr 28 00:46:43 EDT 1999