An experiment on Lowest Unique Integer Games

• We provide first experimental results on three and four player lowest unique integer games.
• We find subjects self-organize themselves into different behavioral classes.
• More than 1/3 of our subjects behaved according to the symmetric mixed strategy Nash equilibrium.
• Those subjects who kept choosing the same number won more frequently than other who did.

We experimentally study Lowest Unique Integer Games (LUIGs) to determine if and how subjects self-organize into different behavioral classes. In a LUIG, N(≥3) players submit a positive integer up to MM and the player choosing the smallest number not chosen by anyone else wins. LUIGs are simplified versions of real systems such as Lowest/Highest Unique Bid Auctions that have been attracting attention from scholars, yet experimental studies are scarce. Furthermore, LUIGs offer insights into choice patterns that can shed light on the alleviation of congestion problems. Here, we consider four LUIGs with N={3,4}N={3,4} and M={3,4}M={3,4}. We find that (a) choices made by more than 1/3 of subjects were not significantly different from what a symmetric mixed-strategy Nash equilibrium (MSE) predicts; however, (b) subjects who behaved significantly differently from what the MSE predicts won the game more frequently. What distinguishes subjects was their tendencies to change their choices following losses.