scholarly journals Correlated disasters and need-based transfers: The limits of risk pooling systems in simulated ecologies

2017 ◽  
Author(s):  
Marco Campenni ◽  
Lee Cronk ◽  
Athena Aktipis
Keyword(s):  
Preferential Attachment ◽  
Management Strategies ◽  
Small World ◽  
Agent Based ◽  
Risk Pooling ◽  
Risk Management Strategies ◽  
Pooling Strategies ◽  
Regular Networks ◽  
Recipient Need ◽  
Parameter Values

ABSTRACTThroughout their evolutionary history, humans have faced risks including drought, disease, natural disasters and other unexpected negative events. To deal with these risks, humans use a variety of risk management strategies, some of which involve relying on others in times of need in order to pool risk. However, the effectiveness of risk pooling strategies can be limited when there is high synchronicity of need. Here we investigate the limits of two resource transfer systems for pooling risk (need-based transfers, NBT, and debt-based transfers, DBT) in simulated ecologies with different degrees of correlated disasters using an agent-based model of the need-based transfer system of the Maasai. Overall, we find that survival is higher when shocks are less correlated among partners, when groups are larger, and when network structure is characterized by preferential attachment networks, which have a more modular structure than regular or small world networks. We also find that NBT strategies consistently outperform DBT strategies across a wide variety of parameter values and that the advantage of NBT over DBT is greatest when shocks are less correlated and group size is small. Our results also suggest that systems of sharing that are based on recipient need are less vulnerable than systems that are based on debt and credit, especially in small world and regular networks.

scholarly journals Preventing a cluster from becoming a new wave in settings with zero community COVID-19 cases

2020 ◽  
Author(s):  
Romesh G Abeysuriya ◽  
Dominic Delport ◽  
Robyn M Stuart ◽  
Rachel Sacks-Davis ◽  
Cliff C Kerr ◽  
...  
Keyword(s):  
Management Strategies ◽  
International Travel ◽  
New Wave ◽  
Agent Based ◽  
Percentage Point Increase ◽  
Point Increase ◽  
Risk Management Strategies ◽  
Community Transmission ◽  
Behavioural Factors ◽  
Border Controls

AbstractIn settings with zero community transmission, any new SARS-CoV-2 outbreaks are likely to be the result of random incursions. The level of restrictions in place at the time of the incursion is likely to considerably affect possible outbreak trajectories. We used an agent-based model to investigate the relationship between ongoing restrictions and behavioural factors, and the probability of an incursion causing an outbreak and the resulting growth rate. We applied our model to the state of Victoria, Australia, which has reached zero community transmission as of November 2020.We found that a future incursion has a 45% probability of causing an outbreak (defined as a 7-day average of >5 new cases per day within 60 days) if no restrictions were in place, decreasing to 23% with a mandatory masks policy, density restrictions on venues such as restaurants, and if employees worked from home where possible. A drop in community symptomatic testing rates was associated with up to a 10-percentage point increase in outbreak probability, highlighting the importance of maintaining high testing rates as part of a suppression strategy.Because the chance of an incursion occurring is closely related to border controls, outbreak risk management strategies require an integrated approaching spanning border controls, ongoing restrictions, and plans for response. Each individual restriction or control strategy reduces the risk of an outbreak. They can be traded off against each other, but if too many are removed there is a danger of accumulating an unsafe level of risk. The outbreak probabilities estimated in this study are of particular relevance in assessing the downstream risks associated with increased international travel.

scholarly journals How to plug out of the networks in jeopardy of ASF, Covid-19, social media or markets toxicity

E-methodology ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 71-84
Author(s):  
ANDRZEJ BUDA ◽  
KATARZYNA KUŹMICZ
Keyword(s):  
Social Media ◽  
Preferential Attachment ◽  
Global Network ◽  
Epidemic Threshold ◽  
Agent Based ◽  
Scale Free ◽  
Nearest Neighbours ◽  
Fully Connected ◽  
Node Removal ◽  
Parameter Values

Aim: In our research, we examine universal properties of the global network whose structure represents a real-world network that might be later extended to social media, commodity market or countries under the infl uence of diseases like Covid-19 or ASF.Methods: We propose quasi-epidemiological agent-based model of virus spread on a network. Firstly, we consider countries represented by subnetworks that have a scale-free structure achieved by the preferential attachment construction with a node hierarchy and binary edges. The global network of countries is a complete, directed, weighted network of thesesubnetworks connected by their capitals and divided into cultural and geographical proximity. Viruses with a defi ned strength or aggressiveness occur independently at one of the nodes of a selected subnetwork and correspond to a piece of products or messages or diseases.Results and conclusion: We analyse dynamics set by varying parameter values and observe a variety of phenomena including local and global pandemics and the existence of an epidemic threshold in the subnetworks. These phenomena have been also shown fromindividual users points of view because the node removal from the network might have impact on its nearest neighbours differently. The selective participation in global network is proposed here to avoid side effects when the global network has been fully connected and no longer divided into clusters.

scholarly journals Friendship, kinship and social risk management strategies among pastoralists in Karamoja, Uganda

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Padmini Iyer
Keyword(s):  
Social Networks ◽  
Risk Management ◽  
Management Strategies ◽  
Safety Net ◽  
Social Risk ◽  
Mutual Aid ◽  
Exchange Networks ◽  
Risk Pooling ◽  
Risk Management Strategies

AbstractThis paper describes risk-pooling friendships and other social networks among pastoralists in Karamoja, Uganda. Social networks are of critical importance for risk management in an environment marked by volatility and uncertainty. Risk management or risk pooling mainly takes the form of “stock friendships”: an informal insurance system in which men established mutually beneficial partnerships with unrelated or related individuals through livestock transfers in the form of gifts or loans. Friends accepted the obligation to assist each other during need, ranging from the time of marriage to times of distress. Anthropologists and economists claim that social networks are critical for recouping short-term losses such as food shortage, as well as for ensuring long-term sustainability through the building of social capital and rebuilding of herds. To this end, I present ethnographic data on friendship, kinship, and other networks among male and female pastoralists in Karamoja. Using qualitative and quantitative data on these relationships and norms of livestock transfers and other mutual aid, I show the enduring importance of social networks in the life of Karamoja’s pastoralists today. I also demonstrate how exchange networks were utilized by participants during a drought. On this basis, I argue that appreciating historical and traditional mechanisms of resilience among pastoralists is vital for designing community-based risk management projects. I discuss how traditional safety net systems have been used successfully by NGOs to assist pastoralists in the wake of disaster, and how the same can be done by harnessing risk-pooling friendships in Karamoja.

scholarly journals Network hubs cease to be influential in the presence of low levels of advertising

2021 ◽  
Vol 118 (7) ◽  
pp. e2013391118
Author(s):  
Gabriel Rossman ◽  
Jacob C. Fisher
Keyword(s):  
Parameter Space ◽  
Preferential Attachment ◽  
Research Question ◽  
Small World ◽  
Opinion Leadership ◽  
External Influence ◽  
Agent Based ◽  
Random Node ◽  
Important People ◽  
Empirical Networks

Attempts to find central “influencers,” “opinion leaders,” “hubs,” “optimal seeds,” or other important people who can hasten or slow diffusion or social contagion has long been a major research question in network science. We demonstrate that opinion leadership occurs only under conventional but implausible scope conditions. We demonstrate that a highly central node is a more effective seed for diffusion than a random node if nodes can only learn via the network. However, actors are also subject to external influences such as mass media and advertising. We find that diffusion is noticeably faster when it begins with a high centrality node, but that this advantage only occurs in the region of parameter space where external influence is constrained to zero and collapses catastrophically even at minimal levels of external influence. Importantly, nearly all prior agent-based research on choosing a seed or seeds implicitly occurs in the network influence only region of parameter space. We demonstrate this effect using preferential attachment, small world, and several empirical networks. These networks vary in how large the baseline opinion leadership effect is, but in all of them it collapses with the introduction of external influence. This implies that, in marketing and public health, advertising broadly may be underrated as a strategy for promoting network-based diffusion.

The management of risk in a dryland environment

2011 ◽  
pp. 13-21
Author(s):  
D.I. Gray ◽  
J.I. Reid ◽  
D.J. Horne
Keyword(s):  
Risk Management ◽  
Service Providers ◽  
Management Strategies ◽  
Subterranean Clover ◽  
Farming Systems ◽  
Market Risk ◽  
Farm Size ◽  
Forage Crops ◽  
Risk Management Strategies ◽  
Upside Risk

A group of 24 Hawke's Bay hill country farmers are working with service providers to improve the resilience of their farming systems. An important step in the process was to undertake an inventory of their risk management strategies. Farmers were interviewed about their farming systems and risk management strategies and the data was analysed using descriptive statistics. There was considerable variation in the strategies adopted by the farmers to cope with a dryland environment. Importantly, these strategies had to cope with three types of drought and also upside risk (better than expected conditions), and so flexibility was critical. Infra-structure was important in managing a dryland environment. Farmers chose between increased scale (increasing farm size) and geographic dispersion (owning a second property in another location) through to intensification (investing in subdivision, drainage, capital fertiliser, new pasture species). The study identified that there may be scope for further investment in infra-structural elements such as drainage, deeper rooting alternative pasture species and water harvesting, along with improved management of subterranean clover to improve flexibility. Many of the farmers used forage crops and idling capacity (reduced stocking rate) to improve flexibility; others argued that maintaining pasture quality and managing upside risk was a better strategy in a dryland environment. Supplementary feed was an important strategy for some farmers, but its use was limited by contour and machinery constraints. A surprisingly large proportion of farmers run breeding cows, a policy that is much less flexible than trading stock. However, several farmers had improved their flexibility by running a high proportion of trading cattle and buffer mobs of ewe hoggets and trade lambs. To manage market risk, the majority of farmers are selling a large proportion of their lambs prime. Similarly, cattle are either sold prime or store onto the grass market when prices are at a premium. However, market risk associated with the purchase of supplements and grazing was poorly managed.

The Effects of Decision Aid Orientation on Risk Factor Identification and Audit Test Planning

2002 ◽  
Vol 21 (2) ◽  
pp. 39-56 ◽  
Author(s):  
Jean C. Bedard ◽  
Lynford E. Graham
Keyword(s):  
Risk Factors ◽  
Risk Management ◽  
Decision Aid ◽  
Decision Aids ◽  
Management Strategies ◽  
Risk Identification ◽  
Matched Pair ◽  
Audit Planning ◽  
Audit Firms ◽  
Risk Management Strategies

In auditing, risk management involves identifying client facts or issues that may affect engagement risk, and planning evidence-gathering strategies accordingly. The purpose of this paper is to examine whether auditors' identification of risk factors and planning of audit tests is affected by decision aid orientation, i.e., a “negative” focus wherein client risk and its consequences are emphasized, or a “positive” focus where such factors are not emphasized. Specifically, we expect that auditors will identify more risk factors using a negatively oriented risk identification decision aid, but only when engagement risk is relatively high. We address this issue in the context of auditors' knowledge of actual clients, manipulating decision aid orientation as negative or positive in a matched-pair design. Results show that auditors using the negative decision aid orientation identify more risk factors than do those using a positive orientation, for their higher-risk clients. We also find that decisions to apply substantive tests are more directly linked to specific risk factors identified than to direct risk assessments. Further, our results show that auditors with repeat engagement experience with the client identify more risk factors. The findings of this study imply that audit firms may improve their risk management strategies through simple changes in the design of decision aids used to support audit planning.

scholarly journals The structure of co-publications multilayer network

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ghislain Romaric Meleu ◽  
Paulin Yonta Melatagia
Keyword(s):  
Power Law ◽  
Degree Distribution ◽  
Preferential Attachment ◽  
Small World ◽  
Generation Model ◽  
Small World Network ◽  
Power Law Distribution ◽  
Multilayer Networks ◽  
Multilayer Network ◽  
Scientific Papers

AbstractUsing the headers of scientific papers, we have built multilayer networks of entities involved in research namely: authors, laboratories, and institutions. We have analyzed some properties of such networks built from data extracted from the HAL archives and found that the network at each layer is a small-world network with power law distribution. In order to simulate such co-publication network, we propose a multilayer network generation model based on the formation of cliques at each layer and the affiliation of each new node to the higher layers. The clique is built from new and existing nodes selected using preferential attachment. We also show that, the degree distribution of generated layers follows a power law. From the simulations of our model, we show that the generated multilayer networks reproduce the studied properties of co-publication networks.

scholarly journals Evaluation of Physical Risk during Necropsy and Morgue Activities as Risk Management Strategy

2021 ◽  
Vol 18 (16) ◽  
pp. 8266
Author(s):  
Zoe Del Fante ◽  
Nicola Di Fazio ◽  
Adriano Papale ◽  
Paola Tomao ◽  
Fabio Del Duca ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Management ◽  
Management Strategies ◽  
Risk Management Strategy ◽  
Work Related ◽  
Activity Measurements ◽  
Risk Management Strategies ◽  
Physical Risk ◽  
Critical Issues ◽  
Load Handling

Physical risk assessments allow us to understand work-related critical issues, thus representing a useful tool in risk management strategies. In particular, our study focuses on the identification of already known and emerging physical risks related to necropsy and morgue activities, as well as crime scene investigations. The aim of our study is, therefore, to identify objective elements in order to quantify exposure to such risk factors among healthcare professionals and working personnel. For the research of potentially at-risk activities, data from the Morgue of Policlinico Umberto I Hospital in Rome were used. The scientific literature has been reviewed in order to assess the risks associated with morgue activity. Measurements were performed on previously scheduled days, in collaboration with the activities of different research units. The identified areas of risk were: microclimate; exposure to noise and vibrations; postural and biomechanical aspects of necropsy activities. The obtained results make it possible to detect interindividual variability in exposure to many of the aforementioned risk factors. In particular, the assessment of microclimate did not show significant results. On the contrary, exposure to vibrations and biomechanical aspects of load handling have shown potential risk profiles. For this reason, both profiles have been identified as possible action targets for risk management strategies.

Persistence and Potential Lethality in Intimate Partner Violence: Evaluating the Concurrent and Predictive Validity of a Dual Risk Assessment Protocol

2021 ◽  
pp. 107780122098834
Author(s):  
Kirk R. Williams ◽  
Richard Stansfield ◽  
Jacquelyn Campbell
Keyword(s):  
Risk Assessment ◽  
Intimate Partner Violence ◽  
Predictive Validity ◽  
Race And Ethnicity ◽  
Partner Violence ◽  
Management Strategies ◽  
Intimate Partner ◽  
Assessment Protocol ◽  
Risk Management Strategies ◽  
Domestic Violence Screening

This study seeks to determine the concurrent and predictive validity of a dual risk assessment protocol. It combines the risk of persistence in intimate partner violence (IPV) measured via the Domestic Violence Screening Instrument–Revised (DVSI-R) with supplemental items from the Danger Risk Assessment (DRA) bearing on the risk of potential lethality. We further test whether this assessment protocol reproduces disparities by race and ethnicity found in the larger population. Using a sample of 4,665 IPV male defendants with a female victim, analyses support both types of criterion validity. The DRA risk score is associated with felony charges, incarceration at the initial arrest, and the frequency of subsequent dangerous behavior. Results also suggest minimal predictive bias or disparate impact by race and ethnicity. Incorporating supplemental items bearing on potential lethality risk adds important information concerning the risk management strategies of those involved in IPV.

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