Xihao Song

I am a second-year PhD student at University of Glasgow supported by Adam Smith Business School.

I work on microeconomic theory, including game theory, decision theory, mechanism design, and matching.

Contact Details

Working Paper

Intertemporal time preference on a simplex in continuous time (R & R at Journal of Mathematical Economics) 

Abstract:

This paper aims to provide a representation theorem for consumption stream in the simplex in continuous time, by using the weaker axiom of ”Agree with”, the strong axiom of “Preferential Independence”, and the axioms of “Separability” and “Measurability” on the simplex, consistent with the spirit of Koopman’s work between 1960-1972, and Epstein’s work in 1983 and 2003. Moreover, it considers a model containing piecewise continuous trajectories on the simplex, such as a portfolio optimization problem, a cake-cutting problem, or a maximization problem with a fixed budget (i,e., time, asset, probability distributions, etc.), which also allows some discontinuous trajectories. 

 

Work in Progress

Dominated Strategy in Random Game (Lisbon Meeting 2023, The 34th International Conference on Game Theory, AEA)

Abstract:

Dominance solvability is one of the simplest and most robust solution concepts first introduced by Moulin (1979)[8] in the context of voting. In contrast, it is rare to come across a game that does not have a strongly (or weakly) dominated strategy for which it would be difficult to characterize. Due to the high time complexity of this question, it is difficult to determine if one agent does not have a strictly dominated strategy. Hence, this study provides two major contributions: computational and economic. First, we show that the probability will go to 1 if M equals N and increases to infinity, moreover there exists a threshold of M while M does not necessarily equal N. In addition, we show this threshold is tight. A second advantage of this work is that it provides an efficient algorithm instead of the natural one discussed above, which reduces the time complexity to O(M (M − 1)N ) from O(M (M − 1 + λlog(N )), where λ is the constant.


Abstract:

Theoretically, this work relaxes the rationality behind IESDS in the normal-form game and Backward Induction in the extensive-form game, namely common p-believe in rationality in the normal-form game and common p-belief in the opponent’s future rationality in the extensive-form game. Exper- imentally, this work uses the experimental data from Masaki, Guillaume, and Sevgi (2023)[1] to verify the result.

Multi-sector assignment problem(Draft as requested)

A new algorithm to random assignment problem

...the one of the strongest motives that leads men to art and science is escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one's own ever shifting desires...    

                                                                                                                                                                                            -Einstein.  A