Choice in ordered-tree-based decision problems

Decision makers often have to choose alternatives which appear in an exogenous structure. For example, consider choosing a dish in a restaurant after going through different menu cards (a menu card for buffet, another for combo offers etc.). The decision maker observes the items displayed (as a list) on a menu card and she switches to another menu card to see the items displayed on it (again in the form of another list). Thus the set of all items appears as an “ordered-tree” to the decision maker. There are other examples of decision making where alternatives appear in the form of an ordered-tree. In this paper we consider the cases of choice from ordered-trees (in particular, “lists of lists”) and characterize the choice functions. We impose the axioms of Backward Consistency and Replacement Indifference on choice functions and obtain characterization results for \(k\) -ary ordered-trees and more general ordered-trees. We show that the results for \(k=2\) are similar to those of (Rubinstein and Salant 2006), in which the cases of choice from lists are considered. However the results for \(k \ge 3\) and general ordered-trees are different and allow for instance, a richer class of tie-breaking rules in special cases.     

Improving the efficiency and robustness of nested sampling using posterior repartitioning

Statistics and Computing - In real-world Bayesian inference applications, prior assumptions regarding the parameters of interest may be unrepresentative of their actual values for a given dataset....     

Diversification and Performance in Developed and Emerging Market Contexts: A Review of the Literature*

The link between diversification and performance has become an important topic for research in diverse fields such as strategic management, industrial organization and financial management. However, a synthesis of the research done in developed and emerging markets is missing. This paper attempts such a synthesis by comparing and contrasting the past cumulative empirical research evidence on the relationship between diversification and firm performance in the context of developed economies to the more recent work in the emerging economies. The empirical literature has been divided into three broad perspectives, and the paper highlights the considerable diversity in its findings in developed and emerging markets across each of these perspectives. Based on this study, it is proposed that related diversification is preferable in developed economies and should be based on specific resources, whereas unrelated diversification is appropriate in emerging economies and should be based on generic resources. Although agency problems exist in both contexts, it is argued that the type of problem differs in developed and emerging markets. The paper concludes by identifying three directions for future research. First, the relationship between diversification and performance should be examined across each industry separately and not in aggregate. Secondly, future research needs to examine the organizational mechanisms required to make diversification successful. Finally, the relationship needs to be examined under unstable and dynamic situations such as the current global economic downturn.