Sharing Variable Returns of Cooperation

A finite set of agents jointly undertake a project. Depending on the aggregate of individual agent characteristics the project runs losses or profits, which have to be shared. This paper adopts the mechanistic view and concentrates on devices that a contingent planner may use in order to share the net profits. The Moulin and Shenker (1994) representation theorem is used to show that additive mechanisms with the constant returns property relate 1 to 1 to rationing methods. Refinements are discussed dealing with monotonicity and equity properties that relate to the dispersion of shares. The second part introduces the notion of a consistent solution. Each rationing method induced by a consistent mechanism is consistent. If such mechanism is continuous as well, then the corresponding rationing method is parametric in the terminology of Young (1998) and Moulin (2000). Most prevalent mechanisms (average, serial, Shapley-Shubik) are consistent as member of the class of incremental mechanisms. Each interval consistent incremental mechanism is shown to be a composition of marginal mechanisms and the average mechanism. Immediately the average mechanism is the unique strongly consistent solution. Finally a characterization of mechanisms within the general class is discussed using super-additivity.

Cost Sharing, Differential Games, and the Moulin-Shenker Rule

The Moulin-Shenker rule (Sprumont (1998)) is a nonlinear solution concept for solving heterogeneous cost sharing problems. The first part of the paper shows an axiomatic characterization of this solution using bounds on cost shares and consistency. The second part is devoted to differential games for heterogeneous production problems. It is shown for 2-player games that by an appropriate choice of the game dynamics there is essentially a unique Markov perfect Nash equilibrium. An axiomatic analysis follows for the appropriate game dynamics, which leads in turn to a strategic characterization of the Moulin-Shenker rule.

Contracts, cost sharing and consistency

Under a contract, agents are not only held to honor the allocation as prescribed by a cost sharing mechanism but also a full description of allocated units and costs once production falls short. For agents leaving the cost sharing problem by taking their demanded units and prepaying the corresponding bill, a contract allows for a reformulation of the cost sharing problem to serve the remaining agents. Consistency requires invariance of cost shares relative to any such reduced cost sharing problem. Under consistency, the proportional mechanisms uniquely satisfy additivity and positivity of cost shares. Exchanging positivity by equal treatment characterizes the set of mechanisms which propose proportional shares for only those agents in the maximal indifference set for some preordering on the rest of nonnegative numbers. This includes egalitarian and average cost sharing. The latter is further characterized by the properties linearity. Under R-consistency, a mechanism is supported by at least one reasonable contract, which meets upperbounds. The class of additive and R-consistent mechanisms is isomorphic to the class of consistent and monotonic rationing methods. Consequently serial cost sharing is R-consistent, whereas Shapley-Shubik is not. Examples are given how the extensive literature on consistent monotonic rationing can be inferred to study and characterize cost sharing mechanisms.

Integrated optical polarizer based on the cross strip interferometer configuration.

A bimodal segment of specific length and thickness between two single mode sections of a planar waveguide can serve as a simple interferometer. The configuration can be realized by etching a wide strip from a dielectric film and forcing a — vertically guided, laterally unguided — beam of light to traverse the strip perpendicularly. A TE-pass polarizer designed on the basis of this concept achieves more that 30dB polarization discrimination with a total length of only 5 micrometers, for air covered Silicon-Oxide/Nitride waveguides at a wavelength of 650 nanometers

Performance Approximation and Design of Pick-and-Pass Order Picking Systems

In this paper, we discuss an approximation method based on G/G/m queuing network modeling using Whitt’s (1983) queuing network analyzer to analyze pick-and-pass order picking systems. The objective of this approximation method is to provide an instrument for obtaining rapid performance estimates (such as order lead time and station utilization) of the order picking system. The pick-and-pass system is decomposed into conveyor pieces and pick stations. Conveyor pieces have a constant processing time, whereas the service times at a pick station depend on the number of order lines in the order to be picked at the station, the storage policy at the station, and the working methods. Our approximation method appears to be sufficiently accurate for practical purposes. It can be used to rapidly evaluate the effects of the storage methods in pick stations, the number of order pickers at stations, the size of pick stations, the arrival process of customer orders, and the impact of batching and splitting orders on system performance.simulation;warehousing;order picking;queuing network;pick-and-pass

Stedelijke criminaliteit en rechtshandhaving in het verleden. Een greep uit recent historisch onderzoek

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De verhouding politie-bevolking in historisch perspectief: wederzijdse afhankelijkheid en stilzwijgende contracten

This article explores police-citizens relations in the 19th- and early-20th-centuries and attempts to demonstrate that these were not as unequivocal as is commonly assumed. While historians approach the modern police as an instrument of coercive state control imposed 'from above' onto a passive population, current policy debates tend to assume that police-citizen relations were friendly and that cops learned from citizens, leading to well-informed and neighbourhood-sensitive policing. I argue that police-citizen relations were not friendly, but all about the negotation of 'tacit contracts' between both parties, that allowed the police to carry out their duties within the boundaries of public tolerance, and the public to take all sorts of small conflicts and demands for aid and assistance to the police. This explains why police intervention was never merely repressive: in order to preserve these precious 'contracts', the police operated selectively, acting only against certain groups and offences, and watching particular city areas