Staffing decisions for heterogeneous workers with turnover

In this paper we consider a firm that employs heterogeneous workers to meet demand for its product or service. Workers differ in their skills, speed, and/or quality, and they randomly leave, or turn over. Each period the firm must decide how many workers of each type to hire or fire in order to meet randomly changing demand forecasts at minimal expense. When the number of workers of each type can by continuously varied, the operational cost is jointly convex in the number of workers of each type, hiring and firing costs are linear, and a random fraction of workers of each type leave in each period, the optimal policy has a simple hire- up-to/fire-down-to structure. However, under the more realistic assumption that the number of workers of each type is discrete, the optimal policy is much more difficult to characterize, and depends on the particular notion of discrete convexity used for the cost function. We explore several different notions of discrete convexity and their impact on structural results for the optimal policy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45844/1/186_2005_Article_33.pd

Probing the Links between Political Economy and Non-Traditional Security: Themes, Approaches, and Instruments

This is a pre-print of an article published in International Politics. The definitive publisher-authenticated version of: Hameiri, Shahar, and Lee Jones. "Probing the links between political economy and non-traditional security: Themes, approaches and instruments." International Politics (2015), is available online at: http://dx.doi.org/10.1057/ip.2015.1In recent decades, the security agenda for states and international organisations has expanded dramatically to include a range of ‘non-traditional’, transnational security issues. It is often suggested that globalisation has been a key driver for the emergence or intensification of these problems, but, surprisingly, little sustained scholarly effort has been made to examine the link between responses to the new security agenda and the changing political economy. This curious neglect largely reflects the mutual blind-spots of the sub-disciplines of International Security Studies and International Political Economy, coupled with the dominance of approaches that tend to neglect economic factors. This special issue, which this article introduces, aims to overcome this significant gap. In particular, it focuses on three key themes: the broad relationship between security and the political economy; what is being secured in the name of security, and how this has changed; and how things are being secured – what modes of governance have emerged to manage security problems. In all of these areas, the contributions point to the crucial role of the state in translating shifting state-economy relations to new security definitions and practices

Epistemic Constraints on Autonomous Symbolic Representation in Natural and Artificial Agents

We set out to address, in the form of a survey, the fundamental constraints upon self-updating representation in cognitive agents of natural and artificial origin. The foundational epistemic problem encountered by such agents is that of distinguishing errors of representation from inappropriateness of the representational framework. Resolving this conceptual difficulty involves ensuring the empirical falsifiability of both the representational hypotheses and the entities so represented, while at the same time retaining their epistemic distinguishability. We shall thus argue that perception-action frameworks provide an appropriate basis for the development of an empirically meaningful criterion for validating perceptual categories. In this scenario, hypotheses about the agent’s world are defined in terms of environmental affordances (characterised in terms of the agent’s active capabilities). Agents with the capability to hierarchically-abstract this framework to a level consonant with performing syntactic manipulations and making deductive conjectures are consequently able to form an implicitly symbolic representation of the environment within which new, higher-level, modes of environment manipulation are implied (e.g. tool-use). This abstraction process is inherently open-ended, admitting a wide-range of possible representational hypotheses — only the form of the lowest-level of the hierarchy need be constrained a priori (being the minimally sufficient condition necessary for retention of the ability to falsify high-level hypotheses). In biological agents capable of autonomous cognitive-updating, we argue that the grounding of such a priori ‘bootstrap’ representational hypotheses is ensured via the process of natural selection

Outsourcing a two-level service process

This paper studies outsourcing decisions for a two-level service process in which the first level serves as a gatekeeper for a second level of experts. The objective of the system operator (the client) is to minimize the sum of staffing costs, customer waiting costs, and mistreatment costs due to unsuccessful attempts by a gatekeeper to solve the customer's problem. The client may outsource all or part of the process to a vendor, and first-best contracts exist when the client outsources only gatekeepers or experts. When the client outsources the entire system as a two-level process, a client-optimal contract may not exist unless the exogenous system parameters satisfy a particular (and unlikely) coordination condition. In addition, optimal incentive-compatible contracts exist when the vendor's structure choice (one level or two levels) can deviate from the client's preference. Finally, we numerically examine how vendor structure choice and labor cost advantages influence the client's optimal outsourcing option. © 2012 INFORMS.link_to_subscribed_fulltex