Discrete Rule Learning in First Price Auctions

We present a hidden Markov model of discrete strategic heterogeneity and learning in first price independent private values auctions. The model includes three latent bidding rules: constant absolute mark-up, constant percentage mark-up, and strategic best response. Rule switching probabilities depend upon a bidder\u27s past auction outcomes and a myopic reinforcement learning dynamic. We apply this model to a new experiment that varies the number of bidders and the auction frame between forward and reverse. We find the proportion of bidders following constant absolute mark-up increases with experience, and is higher when the number of bidders is large. The primary driver here is subjects\u27 increased propensity to switch strategies when they experience a loss (win) reinforcement when following a strategic (heuristic) rule

A hidden Markov model for the detection of pure and mixed strategy play in games

We propose a statistical model to assess whether individuals strategically use mixed strategies in repeated games. We formulate a hidden Markov model in which the latent state space contains both pure and mixed strategies, and allows switching between these states. We apply the model to data from an experiment in which human subjects repeatedly play a normal form game against a computer that always follows its part of the unique mixed strategy Nash equilibrium profile. Estimated results show significant mixed strategy play and non-stationary dynamics. We also explore the ability of the model to forecast action choice

Man versus Nash An experiment on the self-enforcing nature of mixed strategy equilibrium

We examine experimentally how humans behave when they play against a computer which implements its part of a mixed strategy Nash equilibrium. We consider two games, one zero-sum and another unprofitable with a pure minimax strategy. A minority of subjects’ play was consistent with their Nash equilibrium strategy, while a larger percentage of subjects’ play was more consistent with different models of play: equiprobable play for the zero-sum game, and the minimax strategy in the unprofitable game. We estimate the heterogeneity and dynamics of the subjects’ latent mixed strategy sequences via a hidden Markov model. This provides clear results on the identification of the use of pure and mixed strategies and the limiting distribution over strategies. The mixed strategy Nash equilibrium is not self-enforcing except when it coincides with the equal probability mixed strategy, and there is surprising amounts of pure strategy play and clear cycling between the pure strategy states

The Impact of the Covid-19 Pandemic on Economic Behaviours and Preferences: Experimental Evidence from Wuhan

We examine how the emergence of Covid-19 in Wuhan, and the ramifications of associated events, influence pro-sociality, trust and attitudes towards risk and ambiguity. We assess these influences using an experiment consisting of financially incentivized economic tasks. We establish causality via the comparison of a baseline sample collected pre-epidemic with five sampling waves starting from the imposition of a stringent lock- down in Wuhan and completed six weeks later. We find significant long-term increases - measured as the difference between the baseline and final wave average responses - in altruism, cooperation, trust and risk tolerance. Participants who remained in Wuhan during the lockdown exhibit lower trust and cooperation relative to other participants. We identify transitory effects from two events that permeated the public psyche. First, in the immediate aftermath of the Wuhan lockdown, there is a decrease in trust and an increase in ambiguity aversion. Second, the news of a high-profile whistleblower\u27s death also decreases trust while heightening risk aversion

Contingent Payments in Procurement Interactions - Experimental Evidence

A chief objective of creating competition among suppliers is the procurement of higher quality goods at lower prices. When procuring non-standard goods, it is often difficult to write a complete specification of desired quality in the contract. A moral hazard arises when this quality is costly and determined by the supplier ex post to contracting. In an effort to mitigate this moral hazard, we introduce a correlated contingent payment contract. This contract is awarded through competitive bidding. The winning supplier’s payment is, according to a fixed probability, either the amount of their bid or a quality contingent amount that depends on the bid and an exogenous norm for how a seller and buyer split social surplus. We show, both theoretically and experimentally, there is a “Goldilocks” region for high quality to emerge in which the probability of quality contingent payment is large enough to reward high quality provision, but not too large to induce overly aggressive bidding. This optimal implementation only relies upon preferences for maximizing one’s own profit and the rationality of backward induction. A surprising experimental result is that suppliers earned positive economic profits within this region. We estimate a structural model of bounded rationality to show that risk aversion can explain this result. These results have managerial implications for the design of contingent payments in contracts

Speed Traps: Algorithmic Trader Performance Under Alternative Market Structures

Using laboratory experiments, we illustrate that trading algorithms that prioritize low latency pose certain pitfalls in a variety of market structures and configurations. In hybrid double auctions markets with human traders and trading agents, we find superior performance of trading agents to human traders in balanced markets with the same number of human and Zero Intelligence Plus (ZIP) buyers and sellers only, thus providing a partial replication of Das et al. (2001). However, in unbalanced markets and extreme market structures, such as monopolies and duopolies, fast ZIP agents fall into a speed trap and both human participants and slow ZIP agents outperform fast ZIP agents. For human traders, faster reaction time significantly improves trading performance, while Theory of Mind can be detrimental for human buyers, but beneficial for human sellers

Cognitive Abilities and Individual Earnings in Hybrid Continuous Double Auctions

We study the influence of cognitive abilities, in particular reaction time, trader intuition (Theory of Mind), and cognitive reflection abilities, on human participants’ individual earnings when competing alongside algorithmic traders in continuous double auctions. In balanced markets, where each human trader has an algorithmic trader clone with the same valuations or costs, faster human reaction time significantly improves trading performance, while Theory of Mind can be detrimental to human trading performance, particularly for sellers. For unbalanced markets with humans and algorithmic traders on opposite sides of the market, the effects of cognitive abilities depend on trader role as well as agent presence and speed, highlighting the influence of market balance and agent presence and speed on trading success and earnings

Discrete Rule Learning and the Bidding of the Sexes

We present a hidden Markov model of discrete strategic heterogeneity and learning in first price independent private values auctions. The model includes three latent bidding rules: constant absolute mark-up, constant percentage mark-up, and strategic best response. Rule switching probabilities depend upon a bidder's past auction outcomes. We apply this model to a new experiment that varies the number of bidders, the auction frame between forward and reverse, and includes the collection of saliva samples - used to measure subjects' sex hormone levels. We find the proportion of bidders following constant absolute mark-up increases with experience, particularly when the number of bidders is large. The primary driver here is subjects' increased propensity to switch strategies when they experience a loss (win) reinforcement when following a strategic (heuristic) rule. This affect is stronger for women and leads them spend more time following boundedly rational rules. We also find women in the Luteal and Menstrual phases of their menstrual cycle bid less aggressively, in terms of surplus demanded, when following the best response rule. This combined with spending more time following simple rules of thumbs explains gender differences in earnings

Discrete Rule Learning and the Bidding of the Sexes

We present a hidden Markov model of discrete strategic heterogeneity and learning in first price independent private values auctions. The model includes three latent bidding rules: constant absolute mark-up, constant percentage mark-up, and strategic best response. Rule switching probabilities depend upon a bidder's past auction outcomes. We apply this model to a new experiment that varies the number of bidders, the auction frame between forward and reverse, and includes the collection of saliva samples - used to measure subjects' sex hormone levels. We find the proportion of bidders following constant absolute mark-up increases with experience, particularly when the number of bidders is large. The primary driver here is subjects' increased propensity to switch strategies when they experience a loss (win) reinforcement when following a strategic (heuristic) rule. This affect is stronger for women and leads them spend more time following boundedly rational rules. We also find women in the Luteal and Menstrual phases of their menstrual cycle bid less aggressively, in terms of surplus demanded, when following the best response rule. This combined with spending more time following simple rules of thumbs explains gender differences in earnings

An Experimental Study of Within- and Cross-cultural Cooperation: Chinese and American Play in the Prisoner’s Dilemma Game

We study whether cross- and within-culture groups have different cooperation rates in the Prisoner’s Dilemma Game. In an experiment, university students in China and America engage in a single iteration of the game, complete belief elicitation tasks regarding their opponents’ play and take a survey including attitudinal measurements regarding their in- and out-group attitudes. Cooperation rates are higher across the two countries are higher in both cross-culture and in within-culture interactions, although not significantly. We also find that Chinese participants cooperate less than American ones. Further, female Chinese participants are more cooperative than Chinese male ones. In the cross-culture treatment, Chinese participants underestimate the likelihood of cooperative behavior of their American counterparts, while Americans overestimate the same likelihood of their Chinese counterparts. Our results also show that Chinese participants cooperate more conditionally than American ones. Finally, while we find some attitudinal in- and out-biases both they do not generate meaningful impact on cooperative behavior