Component efficient solutions in line-graph games with applications

Recently, applications of cooperative game theory to economic allocation problems have gained popularity. We investigate a class of cooperative games that generalizes some economic applications with a similar structure. These are the so-called line-graph games being cooperative TU-games in which the players are linearly ordered. Examples of situations that can be modeled like this are sequencing situations and water distribution problems. We define four properties with respect to deleting edges that each selects a unique component efficient solution on the class of line-graph games. We interpret these solutions and properties in terms of dividend distributions, and apply them to economic situations. This research has been done while the third author was visiting Tinbergen Institute at the Free University, Amsterdam. The research is part of the Research Programme “Strategic and Cooperative Decision Making” at the Department of Econometrics. Financial support from the Netherlands Organization for Scientific Research (NWO) in the framework of the Russian-Dutch programme for scientific cooperation, is gratefully acknowledged. The third author also appreciates partial financial support from the Russian Leading Scientific Schools Fund (grant 80.2003.6) and Russian Humanitarian Scientific Fund (grant 02-02-00189a). We thank three anonymous referees for their valuable comments.     

Strongly stable networks

We analyze the formation of networks among individuals. In particular, we examine the existence of networks that are stable against changes in links by any coalition of individuals. We show that to investigate the existence of such strongly stable networks one can restrict focus on a component-wise egalitarian allocation of value. We show that when such strongly stable networks exist they coincide with the set of efficient networks (those maximizing the total productive value). We show that the existence of strongly stable networks is equivalent to core existence in a derived cooperative game and use that result to characterize the class of value functions for which there exist strongly stable networks via a “top convexity” condition on the value function on networks. We also consider a variation on strong stability where players can make side payments, and examine situations where value functions may be non-anonymous—depending on player labels.     

Job protection,housing market regulation,and the youth

Young Europeans experience high unemployment rates, job instability, and late emancipation. Meanwhile, they do not support reforms weakening protection on long‐term contracts. In this paper, we suggest a possible rationale for such reform distaste. When the rental market is strongly regulated, landlords screen applicants with regard to their ability to pay the rent. Protecting regular jobs offers a second‐best technology to sort workers, thereby increasing the rental market size. We provide a model where nonemployed workers demand protected jobs despite unemployment and the share of short‐term jobs increases, whereas the individual risk of dismissal is unaffected. Our theory can be extended to alternative risks and markets involving correlated risks and commitment under imperfect information.     

Prediction of the next hypercalcemia free period: application of random effect models with selection on first event

The length of repeated hypercalcemia free periods of patients with bone metastasis of breast cancer with at least one hypercalcemic event was modelled according to a generalized linear mixed model formulated in terms of transition probabilities and according to a latent variable model. In the former case the periods were assumed to be lognormally distributed with two variance components (patients and residue). In the latter case the conditional intensity given a patient was assumed to be the intensity of the Weibull distribution, while the random patient effect (frailty) was assumed to be drawn from a gamma distribution. In both cases the selection of only patients with at least one hypercalcemic event was taken into consideration. In both models the variance of the patient effect turned out to be negligible. For the second and later periods the Weibull appeared to fit better than the lognormal model. For the first period there was almost no information available.     

Would helicopter money be spent? New evidence for the Netherlands

According to some economists, central banks should use ‘helicopter money’ to boost inflation (expectations). Based on a survey among Dutch households, we examine whether respondents would spend the money received via such a transfer. Our results show that respondents expect to spend about 30% of the transfer and that helicopter money would hardly affect inflation expectations. Furthermore, whether transfers come from the central bank or the government makes no difference. Finally, our results suggest that the effect of helicopter money on public trust in the ECB is ambiguous.     

Transforming water infrastructure by linking water management and urban renewal in Rotterdam

Urban water systems have to deal with the impacts of climate change. In response, urban water managers in the city of Rotterdam developed a new water management strategy combining the renewal of water infrastructure with neighborhood revitalization projects. A key factor was the recognition that additional water retention in existing urban areas could only be realized if these projects were linked to urban renewal programs. Moreover, it was acknowledged that through new water retention infrastructure the quality of the social environment of deteriorated neighborhoods could be restored. The results from this historical analysis show that this turn in thinking initiated a successful water policy innovation in Rotterdam, in which the urban water policy is used to solve other urban problems as well by improving the quality of the public amenity. This paper presents key factors that contributed to this process and provides recommendations to further advance the transformation of urban water management infrastructure and the link with spatial planning.     

Use of insertable cardiac monitors for the detection of atrial fibrillation in patients with cryptogenic stroke in the United States is cost-effective

Abstract

Objectives: Atrial fibrillation (AF) is the most common arrhythmia and a major marker of ischemic stroke risk. Early detection is crucial and, once diagnosed, anticoagulation therapy can be initiated to reduce stroke risk. The aim of this study was to assess the cost-effectiveness of employing an insertable cardiac monitor (ICM), BIOMONITOR, for the detection of AF compared to standard of care (SoC) ECG and Holter monitoring in patients with cryptogenic stroke, that is, stroke of unknown origin and where paroxysmal, silent AF is suspected.

Materials and methods: A Markov model was developed which consisted of five main health states reflecting the potential lifetime evolution of the AF disease: post cryptogenic stroke (index event), subsequent mild, moderate and severe stroke, and death. Sub-states were included to track a patient’s AF diagnostic status and the use of antiplatelet or anticoagulant therapy. AF detection was assumed to result in a treatment switch from aspirin to anticoagulants, except among those with a history of major bleeding. Detection yield and accuracy, clinical actions and treatment effects were derived from the literature and validated by an expert clinician. All relevant costs from a US Medicare perspective were included.

Results and conclusions: An ICM-based strategy was associated with a reduction of 37 secondary ischemic strokes per 1000 patients monitored compared with SoC. Total per-patient costs with an ICM were higher (US$90,052 vs. US$85,157) although stroke-related costs were reduced. The use of an ICM was associated with a base-case incremental cost-effectiveness ratio of US$18,487 per life year gained compared with SoC and US$25,098 per quality-adjusted life year gained, below established willingness-to-pay thresholds. The conclusions were found to be robust over a range of input values. From a US Medicare perspective the use of a BIOMONITOR ICM represents a cost-effective diagnostic strategy for patients with cryptogenic stroke and suspected AF.