Latent Separability: Grouping Goods without Weak Separability

This paper develops a new concept of separability with overlapping groups—latent separability. This is shown to provide a useful empirical and theoretical framework for investigating the grouping of goods and prices. It is a generalization of weak separability in which goods are allowed to enter more than one group and where the composition of groups is identified by the choice of group specific exclusive goods. Latent separability is shown to be equivalent to weak separability in latent rather than purchased goods and provides a relationship between separability and household production theory. For the popular class of linear, almost ideal and translog demand models and their generalizations, we provide a method for choosing the number of homothetic separable groups. A detailed method for exploring the composition of the separable groups is also presented. These methods are applied to a long time series of British individual household data on the consumption of twenty two nondurable and service goods.     

Integrating Knowledge through Information Trading: Examining the Relationship between Boundary Spanning Communication and Individual Performance*

With the global penetration of Internet technologies, individuals may now cross organizational boundaries to communicate efficiently with others regardless of time and space. Thus, when looking for help in solving work tasks, knowledge workers may just as easily contact individuals in rival firms across the globe as a coworker sitting at the next desk. As a result, management faces questions such as (1) How should firms manage employees' knowledge‐sourcing activities when they span both intra‐organizational and extra‐organizational boundaries, and (2) What is the relationship between different knowledge‐sourcing activities and individual performance? Grounded in the knowledge‐based view of the firm, we investigate these questions using data from Europe's largest information technology (IT) services and management consulting company. Our results provide evidence that organizations should support boundary spanning and knowledge sourcing from both internal and external sources. Results suggest (1) a positive relationship between boundary spanning communication and creativity and general performance, and (2) a negative relationship between a reliance on colocated coworkers as knowledge sources and creativity.     

State estimation for aoristic models

Aoristic data can be described by a marked point process in time in which the points cannot be observed directly but are known to lie in observable intervals, the marks. We consider Bayesian state estimation for the latent points when the marks are modeled in terms of an alternating renewal process in equilibrium and the prior is a Markov point process. We derive the posterior distribution, estimate its parameters and present some examples that illustrate the influence of the prior distribution. The model is then used to estimate times of occurrence of interval censored crimes.