Tommy Andersson

Transferring Ownership of Public Housing to Existing Tenants : A Market Design Approach

This paper explores a housing market with an existing tenant in each house and where the existing tenants initially rent their houses. The idea is to identify equilibrium prices for the housing market given the prerequisite that a tenant can buy any house on the housing market, including the one that he is currently possessing, or continue renting the house he is currently occupying. The main contribution is the identification of an individually rational, equilibrium selecting, and group non-manipulable price mechanism in a restricted preference domain that contains almost all preference profiles. In this restricted domain, the identified mechanism is the minimum price equilibrium selecting mechanism that transfers the maximum number of ownerships to the existing tenants. We also relate the theoretical model and the main findings to the U.K. Housing Act 1980 whose main objective is to transfer ownerships of houses to existing tenants.

Multi-Item Vickrey-English-Dutch Auctions

Assuming that bidders wish to acquire at most one item, this paper defines a polynomial time multi-item auction that locates the VCG prices in a finite number of iterations for any given starting prices. This auction is called the Vickrey–English–Dutch auction and it contains the Vickrey–English auction [Sankaran, J.K., 1994. On a dynamic auction mechanism for a bilateral assignment problem. Math. Soc. Sci. 28, 143–150] and the Vickrey–Dutch auction [Mishra, D., Parkes, D., 2009. Multi-item Vickrey–Dutch auctions. Games Econ. Behav. 66, 326–347] as special cases. By means of numerical experiments, it is showed that when the auctioneer knows the biddersʼ value distributions, the Vickrey–English–Dutch auction is weakly faster than the Vickrey–English auction and the Vickrey–Dutch auction in 89 percent and 99 percent, respectively, of the investigated problems. A greedy version of the Vickrey–English–Dutch auction is demonstrated to perform even better in the simulation studies.

Least manipulable Envy-free rules in economies with indivisibilities

We consider envy-free and budget-balanced allocation rules for problems where a number of indivisible objects and a fixed amount of money is allocated among a group of agents. In finite economies, we identify under classical preferences each agent’s maximal gain from manipulation. Using this result we find the envy-free and budget-balanced allocation rules which are least manipulable for each preference profile in terms of any agent’s maximal gain. If preferences are quasi-linear, then we can find an envy-free and budget-balanced allocation rule such that for any problem, the maximal utility gain from manipulation is equalized among all agents.

A Competitive Partnership Formation Process

A group of heterogenous agents may form partnerships in pairs. All single agents as well as all partnerships generate values. If two agents choose to cooperate, they need to specify how to split their joint value among one another. In equilibrium, which may or may not exist, no agents have incentives to break up or form new partnerships. This paper proposes a dynamic competitive adjustment process that always either finds an equilibrium or exclusively disproves the existence of any equilibrium in finitely many steps. When an equilibrium exists, partnership and revenue distribution will be automatically and endogenously determined by the process. Moreover, several fundamental properties of the equilibrium solution and the model are derived.

Constrainedly Fair Job Assignments under Minimum Wages

A number of jobs are to be assigned to a greater number of workers. While having to abide by the law of minimum wages, firms must determine who should be assigned which job and at what salary. In such situations fair (envy-free) allocations usually fail to exist. To cope with this situation, this paper proposes a new concept of fairness, called constrained fairness. Among the set of constrainedly fair allocations, the so-called constrainedly fair and minimal allocations are of particular interest. The reason for this is that the salaries are not only compatible with the minimum wages; they are also optimal from the standpoint of cost-minimizing firms and the assignment of jobs is efficient from the viewpoint of workers. A convergent dynamic procedure that identifies constrainedly fair and minimal allocations is proposed. Furthermore, strategic properties of the mechanism are derived, and two notions of efficiency are evaluated.

Sequential Rules for House Allocation with Price Restrictions

This paper considers a housing market with price restrictions. On such market, price equilibrium may be excluded for certain preference profiles. However, the existence of a unique minimal rationing price equilibrium has previously been established on a general preference domain that contains “almost all” preference profiles. This type of equilibrium has been demonstrated to be an important ingredient in a direct and strategy-proof allocation mechanism for housing markets with price restrictions. The main contribution of this paper is to provide a finite ascending price sequence that terminates to a minimal rationing price equilibrium. This sequence is demonstrated to play a key-role in an Iterative English Auction Rule for housing markets with price restrictions.