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Article
Publication date: 5 May 2015

Priscillia Hunt and Jeremy N.V Miles

Studies in criminal psychology are inevitably undertaken in a context of uncertainty. One class of methods addressing such uncertainties is Monte Carlo (MC) simulation…

Abstract

Purpose

Studies in criminal psychology are inevitably undertaken in a context of uncertainty. One class of methods addressing such uncertainties is Monte Carlo (MC) simulation. The purpose of this paper is to provide an introduction to MC simulation for representing uncertainty and focusses on likely uses in studies of criminology and psychology. In addition to describing the method and providing a step-by-step guide to implementing a MC simulation, this paper provides examples using the Fragile Families and Child Wellbeing Survey data. Results show MC simulations can be a useful technique to test biased estimators and to evaluate the effect of bias on power for statistical tests.

Design/methodology/approach

After describing MC simulation methods in detail, this paper provides a step-by-step guide to conducting a simulation. Then, a series of examples are provided. First, the authors present a brief example of how to generate data using MC simulation and the implications of alternative probability distribution assumptions. The second example uses actual data to evaluate the impact that omitted variable bias can have on least squares estimators. A third example evaluates the impact this form of heteroskedasticity can have on the power of statistical tests.

Findings

This study shows MC simulated variable means are very similar to the actual data, but the standard deviations are considerably less in MC simulation-generated data. Using actual data on criminal convictions and income of fathers, the authors demonstrate the impact of omitted variable bias on the standard errors of the least squares estimator. Lastly, the authors show the p-values are systematically larger and the rejection frequencies correspondingly smaller in heteroskedastic error models compared to a model with homoskedastic errors.

Originality/value

The aim of this paper is to provide a better understanding of what MC simulation methods are and what can be achieved with them. A key value of this paper is that the authors focus on understanding the concepts of MC simulation for researchers of statistics and psychology in particular. Furthermore, the authors provide a step-by-step description of the MC simulation approach and provide examples using real survey data on criminal convictions and economic characteristics of fathers in large US cities.

Details

Journal of Criminal Psychology, vol. 5 no. 2
Type: Research Article
ISSN: 2009-3829

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Article
Publication date: 5 May 2015

Jeremy N.V Miles and Priscillia Hunt

In applied psychology research settings, such as criminal psychology, missing data are to be expected. Missing data can cause problems with both biased estimates and lack…

Abstract

Purpose

In applied psychology research settings, such as criminal psychology, missing data are to be expected. Missing data can cause problems with both biased estimates and lack of statistical power. The paper aims to discuss these issues.

Design/methodology/approach

Recently, sophisticated methods for appropriately dealing with missing data, so as to minimize bias and to maximize power have been developed. In this paper the authors use an artificial data set to demonstrate the problems that can arise with missing data, and make naïve attempts to handle data sets where some data are missing.

Findings

With the artificial data set, and a data set comprising of the results of a survey investigating prices paid for recreational and medical marijuana, the authors demonstrate the use of multiple imputation and maximum likelihood estimation for obtaining appropriate estimates and standard errors when data are missing.

Originality/value

Missing data are ubiquitous in applied research. This paper demonstrates that techniques for handling missing data are accessible and should be employed by researchers.

Details

Journal of Criminal Psychology, vol. 5 no. 2
Type: Research Article
ISSN: 2009-3829

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Article
Publication date: 5 May 2015

Jeremy N.V Miles, Magdalena Kulesza, Brett Ewing, Regina A Shih, Joan S Tucker and Elizabeth J D'Amico

When researchers find an association between two variables, it is useful to evaluate the role of other constructs in this association. While assessing these mediation…

Abstract

Purpose

When researchers find an association between two variables, it is useful to evaluate the role of other constructs in this association. While assessing these mediation effects, it is important to determine if results are equal for different groups. It is possible that the strength of a mediation effect may differ for males and females, for example – such an effect is known as moderated mediation. The paper aims to discuss these issues.

Design/methodology/approach

Participants were 2,532 adolescents from diverse ethnic/racial backgrounds and equally distributed across gender. The goal of this study was to investigate parental respect as a potential mediator of the relationship between gender and delinquency and mental health, and to determine whether observed mediation is moderated by gender.

Findings

Parental respect mediated the association between gender and both delinquency and mental health. Specifically, parental respect was a protective factor against delinquency and mental health problems for both females and males.

Practical implications

Demonstrated the process of estimating models in Lavaan, using two approaches (i.e. single group regression and multiple group regression model), and including covariates in both models.

Originality/value

The authors demonstrate the process of estimating these models in Lavaan, using two approaches, a single group regression model and a multiple group model, and the authors demonstrate how to include covariates in these models.

Details

Journal of Criminal Psychology, vol. 5 no. 2
Type: Research Article
ISSN: 2009-3829

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Article
Publication date: 27 August 2021

Jeremy T. Navarre

The global energy industry transports supplies and personnel via helicopter to offshore locations and is increasingly focusing on optimizing upstream logistics. This paper…

Abstract

Purpose

The global energy industry transports supplies and personnel via helicopter to offshore locations and is increasingly focusing on optimizing upstream logistics. This paper aims to and achieves a mutually beneficial balance between research and practice by providing generalizable methods to a problem routinely encountered in practice. Overall, the development and execution of the heterogeneous capacitated helicopter routing problem with split deliveries and multiple depots is validated by the networks’ results.

Design/methodology/approach

Using a unique sample of deepwater and ultra-deepwater permanent offshore locations in the Gulf of Mexico, transportation networks consisting of 57 locations operated by 19 firms are optimized via a randomized greedy algorithm. The study’s randomized greedy algorithm yields depot assignment, vehicle assignment, passenger assignment and routing. All data processing techniques and iterative algorithm processes are defined and explained.

Findings

Results show that the model effectively solves the complex transportation networks consisting of subject firms’ offshore nodes and eligible depots. Specifically, average load factors related to seat capacity and effective vehicle capacity of 87.7 and 95.7% are realized, respectively. The study’s model is a unique contribution to the extant literature and provides researchers and practitioners a practical approach to model development and solution deliverance.

Research limitations/implications

The extant literature encompasses works that inadequately observe the complexity associated with the transportation of personnel. Specifically, this research, unlike many works in the extant literature, uses a heterogeneous versus homogeneous fleet, includes multiple depots versus a single depot and allows split deliveries. Also, the current research ensures all relevant aircraft capabilities and limitations are observed. In particular, the paper takes into account vehicles’ seat capacities, effective capacities via maximum gross takeoff weights and reserve fuel requirements. The current model, which is built upon a heterogeneous capacitated helicopter routing problem with split deliveries and multiple depots (HCHRPSDMD), sufficiently provides a practical approach to model development and solution deliverance while promoting future research endeavors. Future research may use these findings for other geographical regions and similar transportation networks and could adopt firm-specific actual cost parameters instead of the estimated average hourly costs of operating different helicopters. Furthermore, future endeavors may employ other techniques for the derivation of solutions. Future works may be enhanced with actual cost data in lieu of estimations. In the current study, cost data were not available; however, estimations do not inherently proscribe sound interpretations of the models’ outputs. Also, future research endeavors including manual method results may enable comparative results to establish cost variance analysis. Although the current study is, to some extent, limited, the practicality for practitioners and contribution to researchers is comprehensible. Due to the idiosyncrasies and complexity prevalent in modern transportation networks, optimization is and will continue to be a rich opportunity for implementation and research.

Practical implications

As described by previous researchers, energy firms may more efficiently use their contracted aircraft via implementation of a decision-making mechanism for passenger assignment, aircraft selection, depot selection and aircraft routing. Most energy firms possess numerous and spatially segregated offshore facilities and, therefore, are unable to efficiently and effectively make such decisions. Ultimately, the efficient use of firms’ contracted helicopters can enhance profitability via reduced costs without compromising operational performance. Reduced costs are likely to be realized by a potential workforce or workload reduction, reduced flight hours and enhanced bargaining power with commercial helicopter operators. Specifically, enhanced bargaining power may be realized as a result of minimized depots from which the aircraft are operated and an overall reduction of aircraft via increased asset utilization. In essence, the efficient use of commercial helicopters may yield systemic efficiencies that can be shared among all stakeholders, contracting energy firms and commercial helicopter operators. The achievement of operational efficiencies, ultimately, may determine the realization of target performance or solvency of a plethora of firms in the future (Krishnan et al., 2019).

Social implications

For economies, communities and industries depending on crude oil and natural gas production, people’s livelihoods are significantly impacted due to price fluctuations (Rostan and Rostan, 2020; Solaymani, 2019). Based on a unique set of inputs and outputs, the International Energy Agency region (IEA), which includes the current study’s sample set, was found to achieve greater overall production efficiency relative to the Organization of the Petroleum Exporting Countries (OPEC) and the Organization of Arab Petroleum Exporting Countries (OAPEC) (Ohene-Asare et al., 2018). Therefore, enhanced logistics efficiency within the energy industry’s transportation sector across the globe is reasonably likely. For countries relying on these commodities’ exportation, production efficiency is and will continue to be a priority. With limited resources available in industry and society, efficiency is prone to yield advantageous results for all stakeholders. Furthermore, in the context of this study, a reduction of carbon dioxide and noise pollution in air, above water and on land will contribute to society’s drive to protect the environment and preserve our natural resources for future generations.

Originality/value

The current study represents the lone or one of few research endeavors to evaluate the heterogeneous capacitated helicopter routing problem with split deliveries and multiple depots. Furthermore, research pertaining to transportation via helicopter in the Gulf of Mexico’s offshore basin is unprecedented. Lastly, this work yields actionable knowledge for practitioners while enhancing current and promoting future research endeavors.

Details

International Journal of Energy Sector Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1750-6220

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Book part
Publication date: 29 August 2018

Paul A. Pautler

The Bureau of Economics in the Federal Trade Commission has a three-part role in the Agency and the strength of its functions changed over time depending on the…

Abstract

The Bureau of Economics in the Federal Trade Commission has a three-part role in the Agency and the strength of its functions changed over time depending on the preferences and ideology of the FTC’s leaders, developments in the field of economics, and the tenor of the times. The over-riding current role is to provide well considered, unbiased economic advice regarding antitrust and consumer protection law enforcement cases to the legal staff and the Commission. The second role, which long ago was primary, is to provide reports on investigations of various industries to the public and public officials. This role was more recently called research or “policy R&D”. A third role is to advocate for competition and markets both domestically and internationally. As a practical matter, the provision of economic advice to the FTC and to the legal staff has required that the economists wear “two hats,” helping the legal staff investigate cases and provide evidence to support law enforcement cases while also providing advice to the legal bureaus and to the Commission on which cases to pursue (thus providing “a second set of eyes” to evaluate cases). There is sometimes a tension in those functions because building a case is not the same as evaluating a case. Economists and the Bureau of Economics have provided such services to the FTC for over 100 years proving that a sub-organization can survive while playing roles that sometimes conflict. Such a life is not, however, always easy or fun.

Details

Healthcare Antitrust, Settlements, and the Federal Trade Commission
Type: Book
ISBN: 978-1-78756-599-9

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Book part
Publication date: 29 August 2018

Abstract

Details

Healthcare Antitrust, Settlements, and the Federal Trade Commission
Type: Book
ISBN: 978-1-78756-599-9

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Article
Publication date: 1 September 1946

This report is drawn up by the Director‐General of Health and Medical Services for State of Queensland and presented by him to the Minister for Health and Home Affairs of…

Abstract

This report is drawn up by the Director‐General of Health and Medical Services for State of Queensland and presented by him to the Minister for Health and Home Affairs of the State. The report is a record of conscientious and efficient public service by a depleted staff working under great difficulties; over a wide stretch of territory; hampered by shortage of labour and materials for repair or construction. In addition to this was the concentration of large bodies of troops in areas by no means primarily designed for their accommodation. It may be remarked that the huge area now called Queensland was separated from New South Wales in 1859. Its area is 670,000 square miles. Length from north to south 1,300–1,400 miles and from east to west at the widest about 1,000 miles. The greater part lies in the tropics. The east coast and for some distance inland is a trade wind and monsoon belt. With this region the report is mainly concerned. The rainfall diminishes towards west and south. The temperature of the State is by no means excessive. In general the climate is a good one. It is in favour of the public health authorities. On January 1st, 1945, the estimated population was in round figures just over a million, including Brisbane with 384,370. There is closer settlement in the east and along the east coast. Ports, mining and manufactures have developed urban areas so that in addition to Brisbane we have sub‐offices such as Cairns, Toowomba, Townsville, and Rockhampton. Owing to war conditions already referred to, it was not possible without much difficulty for the head quarters staff to carry out sanitary surveys in country areas. It is noted that the limited staff available “carried out all duties assigned to them in the same competent and efficient manner” as before. Rockhampton states that there was only one officer available for a district with a population of 40,000; Cairns that 50 towns were visited with a total of 113 separate visits and a distance of 6,334 miles being traversed. These figures give some idea of the demands made on the sanitary officers. The inspections in one area included anti‐malaria drainage, 39 inspections; malaria investi‐gation, 9; mosquito infestation, 10; swamps, 2; rat infestation, 73; food premises, 77; milk premises, 28; food factories, 129. It will be noticed that much attention is given to the danger of mosquito infestation, with the attendant risk of malaria. In 1943 the Government offered a 50 per cent. subsidy to local authorities for carrying out approved mosquito eradication measures, and though the response was not as great as was expected, the expenditure by those local authorities who, at the time of making this report, had availed themselves of the scheme runs into many thousands of pounds. This was mainly for drainage works, but in addition to this there was spraying and the appointment of additional inspectors. Taking one or two instances, Brisbane expended £173,375; Rockhampton £8,918; Charleville £4,000. It is stated “in Toowomba and to a lesser degree in the other large towns [in the area] the townspeople have become mosquito conscious” and will readily report the presence of even a few mosquitoes. On the other hand in country districts the attitude seems to be that mosquitoes have always been present and will always be present, so “Why worry?” A good instance of bucolic fatalism. After the rains it is obvious that unless water be run off from or sprayed in town puddles and from patches of swampy ground nearby these places become breeding grounds for the nuisance. In the 1944–5 period 696 cases of malaria were notified. Many of these were possibly recurrent attacks among Service and ex‐Service men. Still, the “utmost vigilance” is necessary. The rat nuisance and danger is common to every port in the world. Apart from the fouling and destruction of food and house infestation there is the graver menace of plague. This risk in Queensland most happily seems to be slight, as out of 113,000 examinations of rat bodies and spleen smears no instance of Pasteurella pestis was detected, but again “Vigilance” is the watchword. Poisoning (several kinds of poisons are used), gassing, trapping and hunting are all good within their limits, but rat proofing, removal of harbourages, the use of sanitary rubbish bins, and so forth, are admittedly better, as they strike at the root of the evil. Some seven cities are named where the rat population has not diminished during the last seven years owing to the latter precautions having been more or less neglected. These “starve the rat” and “build out the rat.” Milk claims a large share of attention. The offences are of the kind that we know so well in this country, namely added water and fat deficiency. With regard to added water, some of the figures given range from 19 per cent. to 34 per cent., with, we are glad to note, a correspondingly heavy fine. The Queensland Health Acts prescribe a fine of not less than £1 for each one per centum of added water up to a maximum of £50. It is illegal to carry water on a milk delivery cart when milk is being sold therefrom. Some dishonest vendors had adopted the practice of taking a dip out of a can of water so carried at the instant of delivery to the buyer. It was clearly almost impossible under these circumstances to prosecute successfully a dishonest vendor. Rockhampton states that out of 199 samples of milk officially analysed in the district in the period under review, eleven convictions were obtained for added water, and four for carrying water on the milk delivery van. It is added “Whilst the number of samples of milk which proved to be adulterated with added water was almost twice that of the previous year, it was more than ever apparent that the practice most frequently adopted by offenders is that of carrying water in smaller cans to adulterate the milk when measuring for individual customers.” This evil practice would seem to be widespread, and as its success would seem to depend on delivery from large open containers—an old and almost obsolete method—the remedy is to insist, as far as that be possible having regard to local conditions, that all milk should be pasteurised and sold in bottles. Clearly a person who systematically perpetrates day by day a series of petty frauds on his neighbours is likely to be as careless of their health as he is of their pocket. Pasteurising and bottling are being more widely practised. The periodical examination by the health authorities of milk so treated shows that statutory standards of purity are maintained. Most of the milk sold in Toowomba is pasteurised milk; the same seems to be the case in Townsville, and, as we should expect, in a city such as Brisbane. The game is, or, as we hope, was, an uphill one for milk vendors. Townsville says that local dairymen “still endeavour to carry on under very severe handicaps, such as staff shortages, transport and equipment shortages, and lack of sufficient fodder.” We hope that these drawbacks may by now be referred to in the past tense, for Cairns hopefully stated that “a return to normality is gener ally observable.” During the period under review 2,099 “legal samples” were taken by inspectors in accordance with the provisions of the Health Acts. Of these, 79 85 per cent. passed the standard; 3.95 were adulterated with water; 3.176 were deficient in fat only; 12.44 were below the standard in total solids and/or solids not fat. Of the 2,099 samples taken 1,666 were taken in the “Greater Brisbane Area”; 81.2 per cent. were, it seems, below the standard quality. As the population of the city of Brisbane is about 384,000 it is perhaps not too much to say that 40 per cent. of the total population of the State of Queensland is consuming milk a large proportion of which—about 19 per cent.—is below the standard set by the laws of the State. At Rockhampton 92 out of 135 samples, and at Townsville 28 out of 36, passed the standard. The figures are much the same for seven other towns named and 11 others not named. The results for the whole State is the subject for unfavourable criticism by the Health Department. Proprietary Medicines.—The report states that the prescribing of expensive medicines of this type is a common practice, and that the pharmacist may put the medicine in a different container and usually replaces the proprietary label with his own. “The prescribing of proprietary medicines may maintain the patient's faith in his medical practitioner : it also augments the profit of the pharmacist.” Price fixing has reduced the latter. Homeopathic medicines claim some attention. “As is common with homeopathic medicines those submitted during the year consisted of milk sugar only.” Saccharum lactis seems to be harmless kind of stuff with no particularly marked positive properties. Dose ad lib, says the pharmacopoelig;ia. It is “used for weakly children,” and “diabetics are said to occasionally show slight improvement” by ingesting it. Its normal price is about half‐a‐crown a pound. When, however, it has been “improved ” by the addition of minute traces of the phosphates of calcium, magnesium, and potassium and of calcium fluoride, then made up into tabloid form and sold, the recorded price in one instance had risen to £15 9s. 0d. a pound. The Health Department does not accept an enhanced price to be necessarily a measure of an increase in therapeutic virtues. It observes that“ two hundred tablets of one preparation (a month's course) contained no more mineral substance than one‐third of a teaspoonful of milk,” and after some further remarks to the same purpose, suggests “that in the light of modern therapeutics there would appear to be necessity for health administrations to define their attitude towards homeopathy.” It further quotes responsible medical opinion to the effect that “modern therapeutics has inherited from homeopathy the knowledge of the remarkable power the body possesses of healing itself, if given a chance.” Vitamins. —The grossly exaggerated claims of some food manufacturers and patent medicine manufacturers are referred to. It seems that in 1941 it was suggested to the Queensland Department of Health “that vitamin claims for foods and patent medicines should be re stricted within the known knowledge on the subject or within scientific bounds,” and that the Canadian definition of “vitamin” should be adopted; and that in 1943 the Commonwealth National Health and Medical Research Council recommended that the quantity of each vitamin present in a food should be indicated on the label in units per ounce or pound, and in drugs or medicinal preparations in units per dose. It is perhaps no great exaggeration to say that magic and medicine are still mutually identified in the minds of a sufficient number of people to make the hawking about of what is, in many cases, rubbish, a monetary success. The belief held by such people that what is repeatedly stated must for that and for no other reason be unquestionably true, together with an appeal to their fears and impulses form the psychological basis for success based on the claims made. Thus, it may be said that London, Brisbane, and the aborigines of the Cape York Peninsula are in this respect on much the same level.

Details

British Food Journal, vol. 48 no. 9
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 1 March 1984

Jafar Jafari

Fieldwork is one of the hallmarks of anthropology. Almost all students of anthropology have geographical and cultural specializations, ranging from a small group to a…

Abstract

Fieldwork is one of the hallmarks of anthropology. Almost all students of anthropology have geographical and cultural specializations, ranging from a small group to a nation. Their interest areas are often identified or marked by real or putative boundaries; and it is within these boundaries that anthropologists have “founded” their own villages and tribes — “my village”, “my tribe.”

Details

The Tourist Review, vol. 39 no. 3
Type: Research Article
ISSN: 0251-3102

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Book part
Publication date: 23 August 2019

Eleanor Peters

Abstract

Details

The Use and Abuse of Music: Criminal Records
Type: Book
ISBN: 978-1-78769-002-8

Content available
Article
Publication date: 26 July 2021

Jeremy St John, Karen St John and Bo Han

This study furthers one’s understanding of the motivations of the crowdfunding crowd by empirically examining critical factors that influence the crowd's decision to…

Abstract

Purpose

This study furthers one’s understanding of the motivations of the crowdfunding crowd by empirically examining critical factors that influence the crowd's decision to support a crowdfunding project.

Design/methodology/approach

Backer's comments from a sample of the top 100 most funded technology product projects on KickStarter were collected. A latent Dirichlet allocation (LDA) analysis strategy was adopted to investigate critical motivational factors. Three experts mapped those factors to the known theoretical constructs of social exchange theory (SET).

Findings

Although backers are motivated by value, they are also motivated by far less tangible social factors including trust and a feeling of psychological ownership. Findings suggest that the crowd is far more than a passive group of investors or customers and should be viewed as participatory stakeholders. This study serves as guidance for project owners hoping to motivate the crowd and for future investigators examining backer motivations in other types of crowdsourcing projects.

Research limitations/implications

Online chatter in the form of user-generated comments is an excellent data source for researchers to mine for value and meaning.

Practical implications

Given strong feelings of psychological ownership, project owners should actively engage the crowd and solicit the crowd for advice and help in order to motivate them.

Originality/value

The study presents the first empirical exploration of backer motivations using LDA guided by theory and the knowledge of experts. A framework of latent motivational factors is proposed.

Details

European Journal of Innovation Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1460-1060

Keywords

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