Dilemma game structure observed in traffic flow at a 2-to-1 lane junction.

Using a cellular automaton traffic model based on the stochastic optimal velocity model with appropriate assumptions for both incoming and outgoing vehicle boundaries, the so-called bottleneck issue on a lane-closing section was investigated in terms of game theory. In the system, two classified driver agents coexist: C agents (cooperative strategy) always driving in the first lane and D agents (defective strategy) trying to drive in a lower-density lane whether the first or the second lane. In high-density flow, D agents' interruption into the first lane from the second just before the lane-closing section creates a heavier traffic jam, which reduces social efficiency.

A study on emergence of alternating reciprocity in a 2 x 2 game with 2-length memory strategy.

It is recognized that bilateral cooperation (C), a reward-state in other words, emergently comes up in a 2 x 2 prisoner's dilemma game, if you assume a strategy set with a memory concept. Also observed is a mixture state of cooperation (C) and defect (D), saint- and temptation-state in other words, to obtain a higher payoff than R (R reciprocity) in a hero or leader game that is a chicken-type dilemma game; this phenomenon is called alternating reciprocity (AR) or ST reciprocity. Observing a holistic 2 x 2 game world including trivial games and various dilemma games, where 2-length memory and infinite interactions are assumed, the paper reports on the specific mechanism of AR.

Relationship between dilemma occurrence and the existence of a weakly dominant strategy in a two-player symmetric game.

Defining the dilemma game by the proposition, A game cannot sustain an increase of cooperation strategy in its strategy distribution, we deduced that the substance of a dilemma can be expressed by a productive summation of the static factor and the dynamic factor independently. A static factor is an element of the game's structure that influences a possible dilemma, which relates to a game's structural deviation from a situation where the cooperation strategy can be weakly dominant over other strategies. In contrast, a dynamic factor refers to a strategy distribution's influence on the dilemma by affecting the game dynamics.