Full substitutability

Full Substitutability∗

Various forms of substitutability are essential for establishing the existence of equilibria and other useful properties in diverse settings such as matching, auctions, and exchange economies with indivisible goods. We extend earlier models’ definitions of substitutability to settings in which each agent can be both a buyer in some transactions and a seller in others, and show that all these de...

Online Appendices for “Full Substitutability”

Full Dynamic Substitutability by SAT Encoding

Symmetry in constraint problems can be exploited to greatly improve search performance. A form of symmetry that has been the subject of considerable research is value interchangeability. Automatically detecting full interchangeability is thought to be intractable, so research has focused on either discovery of local interchangeability or programmer knowledge of full interchangeability. This pap...

Testing substitutability

We provide an algorithm for testing the substitutability of a length-N preference relation over a set of contracts X in time O(|X| ·N). Access to the preference relation is essential for this result: We show that a substitutability-testing algorithm with access only to an agent’s choice function must make an expected number of queries exponential in |X|. An analogous result obtains when the age...

Non-Separability and Substitutability

The design and implementation of environmental policy often involves more than one pollutant, and must consider pollution as a byproduct of the production of marketable output. In this paper, we test the implicit assumption in the empirical literature that (1) production of marketable output, pollution, and abatement are separable, and (2) different pollutants can be abated separately. Using un...