Behrooz Hassani-Mahmooei

Climate change and internal migration patterns in Bangladesh: an agent-based model

Bangladesh is one of the countries most vulnerable to climate change impacts such as extreme weather events, due to its low-lying topography, high population density and widespread poverty. In this paper, we report on the development and results of an agent-based model of the migration dynamics that may arise in Bangladesh as a result of climate change. The main modules are each calibrated with data on relevant indicators, such as the incidences of extreme poverty, socioeconomic vulnerability, demography, and historical drought, cyclone and flood patterns. The results suggest likely changes in population densities across Bangladesh due to migration from the drought-prone western districts and areas vulnerable to cyclones and floods in the south, towards northern and eastern districts. The model predicts between 3 and 10 million internal migrants over the next 40 years, depending on the severity of the hazards. Some associated policy considerations are also discussed.

Prescription opioid dispensing and prescription opioid poisoning: Population data from Victoria, Australia 2006 to 2013

Objective: To describe recent trends in opioid prescribing and prescription opioid poisoning resulting in hospitalisation or death in Victoria, Australia.

Use of antidepressant medication after road traffic injury

OBJECTIVES Mental ill health after road traffic injury is common, as is the use of antidepressant medication after injury. Little is known about antidepressant use by injured people prior to their injury. The aim of this study is to describe the nature and extent of antidepressant use before and after road traffic injury. METHODS Victorian residents who claimed Transport Accident Commission (TAC) compensation for a non-catastrophic injury that occurred between 2010 and 2012 and provided consent for Pharmaceutical Benefits Scheme (PBS) linkage were included (n=734). PBS records dating from 12 months prior through to 12 months post injury were provided by the Department of Human Services (Canberra). PBS and TAC claims data were linked. RESULTS Among participants, 12% used antidepressants before injury (84.4D efined Daily Doses/1000 person-days) and 17% used antidepressants after injury (114.1DDD/1000p-d). Only 7.7% of the injured cohort commenced antidepressant treatment post injury. Thus, of all post-injury antidepressant use, 45% could potentially be related to the incident injury, with the remaining 55% most probably a continuation of pre-injury use. Pre-injury use was more common among women (109.4 vs. 54.6 DDD/1000p-d, p<0.0001), and those with whiplash injury (119.3 vs. 73.1, p=0.03). Cyclists and motorcyclists were less likely to use antidepressants pre-injury than car drivers (18.3 vs. 16.9 vs. 109.3, respectively; p<0.001). CONCLUSIONS Less than half of post-injury antidepressant use could potentially be attributable to the incident injury. These results highlight the importance of obtaining information on pre-injury health status before interpreting post-injury health service use to be an outcome of the injury in question.

Dynamics of effort allocation and evolution of trust: an agent-based model

Trust is a dynamic and complex phenomenon and understanding the factors which affect its formation, evolution and disappearance is a critical research issue. It has been shown that trust plays a key role in how human and social capital develop, how economies grow and how societies progress. In this paper, we present an agent-based model of the relations between a dynamic effort allocation system, an evolving trust framework and a reputation module to study how changes in micro-level rent-seeking traits and decisions can shape the emergence of trust across the simulated environment. According to our results, variations in trust are correlated more with the returns to being productive, rather than rent-seeking. In line with previous studies, our model shows that higher than average levels of risk-taking by agents lead to further trust and gains during an interaction, though taken to an extreme, both trust and gain can decline as a result of reckless decisions. We also report on the formation of trust clusters in our model as an emergent phenomenon.

Identity, Authority and Evolution of Order: The Trajectory of Dueling Simulated

Borrowing from public choice literature, while aristocratic civil wars can be regarded as anarchy, and the monopoly of violence by the state as Leviathan, duel of honor is an orderly anarchy. The sudden or gradual withering of duel of honor as an institution marks the transition to the monopoly of violence by the state in Europe. In this paper, we endeavor to capture this transition by introducing a computational model where a simulated agent considers three sets of factors to make its dueling decision: 1) its own characteristics such as dueling skill; 2) its identity such as the reaction received from other members of its own social group; and finally 3) the reaction of the authority such as the possible punishment that could be inflicted by the state against dueler. These factors then interact through a dynamic utility function affected by both optimization and learning processes. The results of our agent-based computational model which are validated against the historical evidence from England, France, and Germany show that a complex, aggregative historical process may be consistently explained on the basis of rational choice of heterogeneous individual agents conditioned by their group identity and authority (organizational) influence.

A population-based study of treated mental health and persistent pain conditions after transport injury

BACKGROUND Persistent pain and mental health conditions often co-occur after injury, cause enormous disability, reduce social and economic participation, and increase long-term healthcare costs. This study aimed to characterise the incidence, profile and healthcare cost implications for people who have a treated mental health condition, persistent pain, or both conditions, after compensable transport injury. METHODS The study comprised a population cohort of people who sustained a transport injury (n = 74,217) between 2008 to 2013 and had an accepted claim in the no-fault transport compensation system in Victoria, Australia. Data included demographic and injury characteristics, and payments for treatment and income replacement from the Compensation Research Database. Treated conditions were identified from 3 to 24-months postinjury using payment-based criteria developed with clinical and compensation system experts. Criteria included medications for pain, anxiety, depression or psychosis, and services from physiotherapists, psychologists, psychiatrists, and pain specialists. The data were analysed with Cox Proportional Hazards regression to examine rates of treated conditions, and general linear regression to estimate 24 month healthcare costs. RESULTS Overall, the incidence of treated mental health conditions (n = 2459, 3.3%) and persistent pain (n = 4708, 6.3%) was low, but rates were higher in those who were female, middle aged (35-64 years), living in metropolitan areas or neighbourhoods with high socioeconomic disadvantage, and for people who had a more severe injury. Healthcare costs totalled more than

0164 Early reporting incentives to reduce time between injury and claim: a multiple baseline interrupted time series analysis of two australian workers’ compensation jurisdictions

A707 M, and people with one or both conditions (7.7%) had healthcare costs up to 7-fold higher (adjusting for demographic and injury characteristics) in the first 24 months postinjury than those with neither condition. CONCLUSIONS The incidence of treated mental health and persistent pain conditions was low, but the total healthcare costs for people with treated conditions were markedly higher than for people without either treated condition. While linkage with other public records of treatment was not possible, the true incidence of treated conditions is likely to be even higher than that found in this study. The present findings can be used to prioritise the implementation of timely access to treatment to prevent or attenuate the severity of pain and mental health conditions after transport injury.

Production and Conflict with Collaborative Agents

Background Early access to healthcare and work rehabilitation services provided by workers’ compensation is associated with faster return to work and reduced claim costs. Incentivising employers to report claims early following injury may reduce time to service access and improve injured worker outcomes. We investigated the impact of legislated early reporting incentives on claim processing time in two Australian workers’ compensation jurisdictions. Methods A multiple baseline interrupted time series (ITS) design was used to evaluate incentive impact on claim processing time using Australian administrative workers’ compensation data. We compared median days between injury and lodgement (lodgement time), lodgement and claim acceptance (decision time), and total processing time in South Australia (SA) and Tasmania (TAS). Results Total time was not immediately affected by incentives, though there was a significant downward trend of one-third a day per month in both jurisdictions relative to the comparator. Lodgement time decreased significantly in both jurisdictions, though the magnitude of impacts differed. A concurrent increase in decision time was observed in TAS but not in SA. Conclusions Our findings suggest that employer focused early reporting incentives may have long-term impacts on claim processing time. However, we also observed unanticipated effects such as increases to insurer decision making time, as well as differential impacts between jurisdictions despite identical policy intent. While co-occurring events such as other legislative changes limit causal inferences, ITS analyses provide a useful approach for investigating the impact of legislative change on policy relevant outcomes in workers’ compensation systems.

The Complexities of Agent-Based Modeling Output Analysis

In this paper we discuss an agent-based model capable of capturing important features of production and conflict before introducing a module to simulate collaborative decisions between agents. Collaboration may happen at the information or process level and can lead to changes in agents’ behaviors and allocations. The results show that when agents share their information they make better decisions at the individual level and economic growth also increases. Collaboration for protection makes the protection more effective, but other agents may also collaborate in their predation, counteracting the protective effect of greater collaboration. The results also confirm that in environments with heterogeneous agents that include predatory behavior, collaboration over the protection of property rights can effectively increase production and wealth.