On the exhaustiveness of truncation and dropping strategies in many-to-many matching markets

We consider two–sided many–to–many matching markets in which each worker may work for multiple firms and each firm may hire multiple workers. We study individual and group manipulations in centralized markets that employ (pairwise) stable mechanisms and that require participants to submit rank order lists of agents on the other side of the market. We are interested in simple preference manipulations that have been reported and studied in empirical and theoretical work: truncation strategies, which are the lists obtained by removing a tail of least preferred partners from a preference list, and the more general dropping strategies, which are the lists obtained by only removing partners from a preference list (i.e., no reshuffling). We study when truncation / dropping strategies are exhaustive for a group of agents on the same side of the market, i.e., when each match resulting from preference manipulations can be replicated or improved upon by some truncation / dropping strategies. We prove that for each stable mechanism, truncation strategies are exhaustive for each agent with quota 1 (Theorem 1). We show that this result cannot be extended neither to group manipulations (even when all quotas equal 1 – Example 1), nor to individual manipulations when the agent’s quota is larger than 1 (even when all other agents’ quotas equal 1 – Example 2). Finally, we prove that for each stable mechanism, dropping strategies are exhaustive for each group of agents on the same side of the market (Theorem 2), i.e., independently of the quotas.

The Bureaucratic Impact of the mobilization for Land. Lessons from the Liberal Republic

The State-building process must be understood through the study of the agencies in charge of each of its regulatory functions. One such function is the regulation of property rights. During the Liberal Republic, as a reaction to the massive mobilization,new tools to better regulate property rights were promoted: colonization, parceling, the award of public lands and, at the end, a new legal framework. In spite of its purposes, they faced and failed to solve the challenges every organization experiences when growing: resource scarcity, controlling its agents, and keeping technical simplicity.

Advances and limitations in the attention to the problems of housing and urban land in Mexico. An approach from the legal-institutional frame

In this work we analyze the reforms carried out by the Mexican state in the nineties of the 20th century, in the items concerning the policies of housing and urban land, based on an exhaustive review of the main actions, programs and changes in the legal and institutional frame that applies for each of these fields. The nineties represent a "breaking point" in the way the State considers the satisfaction of the right to the housing and attends the offer of urbanized land for a tidy and sustainable urban development. In this period of time, the approach of direct intervention in developing and financing housing and creation of land reserves has changed into another one, ruled by the logic of the market. The balance to the first decade of the 21st century is ambiguous, as neither the housing policy has solved the housing shortage for low-income population, nor the land policy has eliminated the illegal urban growth.