Search arXiv⌕ Search

arXiv subjects

Chowdhury Mohammad Sakib Anwar

Publications and source records attributed to Chowdhury Mohammad Sakib Anwar.

7 recordsLinked to original sources

Playing Against the Machine: Cooperation, Communication, and Strategy Heterogeneity in Repeated Prisoner's Dilemma

We study whether communication sustains cooperation when the partner is an artificial intelligence. In a laboratory experiment (n = 234), human participants play indefinitely repeated Prisoner's Dilemma games against an AI chatbot (GPT-5.2) under one of three conditions: no communication, free-form chat before the first round of each supergame, or free-form chat before every round. A fourth treatment replaces the AI with another participant under the every-round protocol. Communication is the main determinant of cooperation with the AI, and a single exchange is enough: pre-play chat raises cooperation from 49% to 84%, while chatting before every round adds less than one percentage point, in contrast to the timing effect found between humans. Once communication is available, cooperation with the AI is no lower than with a human partner, so we find no evidence of the 'machine penalty' documented in the psychology literature. The partner's identity nonetheless shifts strategies: under identical communication, participants tend to reciprocate against a human but to cooperate unconditionally against the AI. Participants also keep their promises to cooperate while carrying out their threats to punish only about half the time. The AI opens cooperatively and rarely defects first, so these differences originate on the human side.

econ.GN↗

Public Good Provision with a Governor

We study a public good game with N citizens and a Governor who allocates resources from a common fund. Citizens may voluntarily contribute or be compelled to do so if audited, in which case shirkers face a penalty. The Governor decides how much of the fund to devote to public good provision, with the remainder embezzled. Crucially, the Governor's utility combines material payoffs from embezzlement with belief-dependent reputational concerns. We fully characterize the symmetric subgame perfect equilibria (SSPE) of the game. The model always admits at least one pure-strategy equilibrium, ranging from universal free-riding with complete embezzlement to full contribution with efficient provision. Mixed-strategy equilibria exist only in a narrow region of parameter values and may involve multiple equilibria. Our analysis highlights the roles of penalties, audits, and reputational incentives in sustaining contribution and provision, thereby linking public good provision with the broader literature on corruption, embezzlement, and psychological game theory.

econ.TH↗

Position Uncertainty in a Prisoner's Dilemma Game : An Experiment

Gallice and Monzon (2019) present a natural environment that sustains full cooperation in one-shot social dilemmas among a finite number of self-interested agents. They demonstrate that in a sequential public goods game, where agents lack knowledge of their position in the sequence but can observe some predecessors' actions, full contribution emerges in equilibrium due to agents' incentive to induce potential successors to follow suit. Furthermore, they show that this principle extends to a number of social dilemmas, with the prominent example that of the prisoner's dilemma. In this study, we experimentally test the theoretical predictions of this model in a multi- player prisoner's dilemma environment, where subjects are not aware of their position in the sequence and receive only partial information on past cooperating actions. We test the predictions of the model, and through rigorous structural econometric analysis, we test the descriptive capacity of the model against alternative behavioural strategies, such as conditional cooperation, altruistic play and free-riding behaviour. We find that the majority resorts to free-riding behaviour, around 30% is classified as Gallice and Monzon (2019) types, followed by those with social preference considerations and the unconditional altruists.

econ.GN↗

Efficient Public Good Provision Between and Within Groups

We generalize the model of Gallice and Monzon (2019) to incorporate a public goods game with groups, position uncertainty, and observational learning. Contributions are simultaneous within groups, but groups play sequentially based on their observation of an incomplete sample of past contributions. We show that full cooperation between and within groups is possible with self-interested players on a fixed horizon. Position uncertainty implies the existence of an equilibrium where groups of players conditionally cooperate in the hope of influencing further groups. Conditional cooperation implies that each group member is pivotal, so that efficient simultaneous provision within groups is an equilibrium.

econ.TH↗

Position Uncertainty in a Sequential Public Goods Game: An Experiment

Gallice and Monzón (2019) present a natural environment that sustains full co-operation in one-shot social dilemmas among a finite number of self-interested agents. They demonstrate that in a sequential public goods game, where agents lack knowledge of their position in the sequence but can observe some predecessors' actions, full contribution emerges in equilibrium due to agents' incentive to induce potential successors to follow suit. In this study, we aim to test the theoretical predictions of this model through an economic experiment. We conducted three treatments, varying the amount of information about past actions that a subject can observe, as well as their positional awareness. Through rigorous structural econometric analysis, we found that approximately 25% of the subjects behaved in line with the theoretical predictions. However, we also observed the presence of alternative behavioural types among the remaining subjects. The majority were classified as conditional co-operators, showing a willingness to cooperate based on others' actions. Some subjects exhibited altruistic tendencies, while only a small minority engaged in free-riding behaviour.

econ.GN↗

Pricing and Electric Vehicle Charging Equilibria

We study equilibria in an Electric Vehicle (EV) charging game, a cost minimization game inherent to decentralized charging control strategy for EV power demand management. In our model, each user optimizes its total cost which is sum of direct power cost and the indirect dissatisfaction cost. We show that, taking player specific price independent dissatisfaction cost in to account, contrary to popular belief, herding only happens at lower EV uptake. Moreover, this is true for both linear and logistic dissatisfaction functions. We study the question of existence of price profiles to induce a desired equilibrium. We define two types of equilibria, distributed and non-distributed equilibria, and show that under logistic dissatisfaction, only non-distributed equilibria are possible by feasibly setting prices. In linear case, both type of equilibria are possible but price discrimination is necessary to induce distributed equilibria. Finally, we show that in the case of symmetric EV users, mediation cannot improve upon Nash equilibria.

econ.TH↗

A Group Public Goods Game with Position Uncertainty

We model a dynamic public good contribution game, where players are (naturally) formed into groups. The groups are exogenously placed in a sequence, with limited information available to players about their groups' position in the sequence. Contribution decisions are made by players simultaneously and independently, and the groups' total contribution is made sequentially. We try to capture both inter and intra-group behaviors and analyze different situations where players observe partial history about total contributions of their predecessor groups. Given this framework, we show that even when players observe a history of defection (no contribution), a cooperative outcome is achievable. This is particularly interesting in the situation when players observe only their immediate predecessor groups' contribution, where we observe that players play an important role in motivating others to contribute.

econ.TH↗