150 research outputs found

    Semiparametric estimation of (constrained) ultrametric trees

    Get PDF
    This paper introduces a general, formal treatment of dynamic constraints, i.e., constraints on the state changes that are allowed in a given state space. Such dynamic constraints can be seen as representations of "real world" constraints in a managerial context. The notions of transition, reversible and irreversible transition, and transition relation will be introduced. The link with Kripke models (for modal logics) is also made explicit. Several (subtle) examples of dynamic constraints will be given. Some important classes of dynamic constraints in a database context will be identified, e.g. various forms of cumulativity, non-decreasing values, constraints on initial and final values, life cycles, changing life cycles, and transition and constant dependencies. Several properties of these dependencies will be treated. For instance, it turns out that functional dependencies can be considered as "degenerated" transition dependencies. Also, the distinction between primary keys and alternate keys is reexamined, from a dynamic point of view.

    A Rapid Reaction to O\u27Bannon: The Need for Analytics in Applying the Sherman Act to Overly Restrictive Joint Venture Schemes

    Get PDF
    This Article reviews the recent and highly publicized district court decision holding that NCAA rules, which bar student-athletes from any compensation for image rights, violated the Sherman Act, and that big-time athletic programs could lawfully agree among themselves to limit compensation to $5,000 annually in trust for each athlete upon leaving school. This Article briefly discusses why the decision correctly found the current rule to be illegal, but also details why, under settled antitrust law, the critical question of how much compensation would significantly harm consumer appeal for college football and basketball is a question better left to marketing science experts. This Article then explains why neither the flawed survey offered in evidence by the NCAA, nor the anecdotal testimony of NCAA officials, should have been credited. Rather, this Article proposes, as a superior alternative, the use of conjoint analysis, a well-recognized technique of marketing science analytics employed to answer the critical legal question that the antitrust doctrine asks in cases like this

    Selecting Competitive Tactics: Try a Strategy Map

    Get PDF
    When developing strategy, a manager considers how various tactics will affect short-term performance and broad strategic direction. The skilled manager keeps those factors in mind and, simultaneously, gauges what the competition is up to. The authors describe a mapping technique that will help managers to do just that. Not only does the technique provide an accessible measure of relative competitive standing, but it also allows managers to simulate tactical changes and analyze their probably impact on business performance

    A new stochastic path-length tree methodology for constructing communication networks

    Full text link
    Network analysis has become a popular method for identifying the communication structure in a system where positional and relational aspects are important. In this paper, a maximum likelihood based methodology is presented that allows for the analysis of binary sociometric data. This methodology provides a network representation via estimated path-length or additive trees that indicate the distance between all pairs of members. The methodology is distinguished from traditional hierarchical clustering based procedures by its direct consideration of the asymmetry in a typical communication process, the simultaneous representation of structural characteristics (e.g., clique membership, clique cohesiveness), and the identification of the specialized communication roles of each member (e.g., opinion leader, liaison). A penalty function algorithm is developed and its performance is investigated via a Monte Carlo analysis with synthetic data. An application examining information flows among managers is presented. Finally, directions for future research are suggested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29291/1/0000352.pd

    Accommodating the effects of brand unfamiliarity in the multidimensional scaling of preference data

    Full text link
    This paper presents a multidimensional scaling (MDS) methodology (vector model) for the spatial analysis of preference data that explicitly models the effects of unfamiliarity on evoked preferences. Our objective is to derive a joint space map of brand locations and consumer preference vectors that is free from potential distortion resulting from the analysis of preference data confounded with the effects of consumer-specific brand unfamiliarity. An application based on preference and familiarity ratings for ten luxury car models collected from 240 consumers who intended to buy a luxury car within a designated time frame is presented. The results are compared with those obtained from MDPREF, a popular metric vector MDS model used for the scaling of preference data. In particular, we find that the consumer preference vectors obtained from the proposed methodology are substantially different in orientation from those estimated by the MDPREF model. The implications of the methodology are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47094/1/11002_2004_Article_BF00994083.pd

    Market Segment Derivation and Profiling Via a Finite Mixture Model Framework

    Full text link
    The Marketing literature has shown how difficult it is to profile market segments derived with finite mixture models, especially using traditional descriptor variables (e.g., demographics). Such profiling is critical for the proper implementation of segmentation strategy. We propose a new finite mixture modelling approach that provides a variety of model specifications to address this segmentation dilemma. Our proposed approach allows for a large number of nested models (special cases) and associated tests of (local) independence to distinguish amongst them. A commercial application to customer satisfaction is provided where a variety of different model specifications are tested and compared.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46979/1/11002_2004_Article_399784.pd

    A parametric procedure for ultrametric tree estimation from conditional rank order proximity data

    Full text link
    The psychometric and classification literatures have illustrated the fact that a wide class of discrete or network models (e.g., hierarchical or ultrametric trees) for the analysis of ordinal proximity data are plagued by potential degenerate solutions if estimated using traditional nonmetric procedures (i.e., procedures which optimize a STRESS-based criteria of fit and whose solutions are invariant under a monotone transformation of the input data). This paper proposes a new parametric, maximum likelihood based procedure for estimating ultrametric trees for the analysis of conditional rank order proximity data. We present the technical aspects of the model and the estimation algorithm. Some preliminary Monte Carlo results are discussed. A consumer psychology application is provided examining the similarity of fifteen types of snack/breakfast items. Finally, some directions for future research are provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45756/1/11336_2005_Article_BF02294429.pd
    • …
    corecore