Optimal auctions with multidimensional types and the desirability of exclusion

Within the context of a single-unit, independent private values auction model, we show that if bidder types are multidimensional, then under the optimal auction exclusion of some bidder types will occur. A second contribution of the paper is methodological in nature. In particular, we identify conditions under which an auction model with multidimensional types can be reduced to a model with one dimensional types without loss of generality. Reduction results of this type have achieved the status of folklore in the mechanism design literature. Here, we provide a proof of the reduction result for auctions.

Abstract types and distributions in independent private value auctions

In this note, in an independent private values auction framework, I discuss the relationship between the set of types and the distribution of types. I show that any set of types, finite dimensional or not, can be extended to a larger set of types preserving incentive compatibility constraints, expected revenue and bidder’s expected utilities. Thus for example we may convexify a set of types making our model amenable to the large body of theory in economics and mathematics that relies on convexity assumptions. An interesting application of this extension procedure is to show that although revenue equivalence is not valid in general if the set of types is not convex these mechanism have underlying distinct allocation mechanism in the extension. Thus we recover in these situations the revenue equivalence.

Optimal taxation with gradual learning of types

An important feature of life-cycle models is the presence of uncertainty regarding one’s labor income. Yet this issue, long recognized in different areas, has not received enough attention in the optimal taxation literature. This paper is an attempt to fill this gap. We write a simple 3 period model where agents gradually learn their productivities. In a framework akin to Mirrlees’ (1971) static one, we derive properties of optimal tax schedules and show that: i) if preferences are (weakly) separable, uniform taxation of goods is optimal, ii) if they are (strongly) separable capital income is to rate than others forms of investiment.

A sociometric analysis for the creation of an integrated multicultural work team

This research aimed to apply the sociometric theory and its methodology to create an integrated multicultural work team. The study focused on the application of the sociometry theory, developed by Jacob L. Moreno in 1934, to analyze the small multicultural group. In the beginning, a review of the literature was done to have a better understanding of Sociometric Theory as well as the modern tools and software developed to analyze and map the social networks. After this part of the study, the qualitative study was done, in which 26 students from 12 countries, which studied together in a Corporate International Master (2014-2015), developed by Georgetown University’s McDonough School of Business, Corporate Master of Business Administration from ESADE Business School and FGV/EBAPE, were surveyed and asked them to choose people, among the selected group, who they attracted, rejected or they were neutral towards, in 4 different scenarios: work team, leadership, trip (leisure time) and personal problem. Additionally, there were, two questions asked about how they felt when they answered the survey and which question(s) was/were difficult to answer and why. The focus on these two questions was to understand the emotional state of the respondents when they answered the survey and related this emotional state to the Sociometric Theory. The sociometric matrix, using Microsoft Excel, was created using the answers and the total of the positive, negative and neutral choices were analyzed for each scenario as well as the mutualities and incongruences of the choices. Furthermore, the software Kumu was used to analyze the connections between the people in the selected group using three metrics: size, degree centrality and indegree. Also Kumu was used to draw the social maps or sociometric maps. Using the relationship level analyses of the sociometric matrix and maps, it was possible to create an integrated multicultural work team. In the end, the results obtained suggest that it is possible to apply the sociometric methodology to study the relationships inside companies, project teams and work teams and identify the best work team based on the interrelationship between the people as well as the lack of communication among the team members, project team or inside the company as a whole.