Single Imputation Methods and Confidence Intervals for the Gini Index

The problem of missing data is a common feature in any study, and a single imputation method is often applied to deal with this problem. The first contribution of this paper is to analyse the empirical performance of some traditional single imputation methods when they are applied to the estimation of the Gini index, a popular measure of inequality used in many studies. Various methods for constructing confidence intervals for the Gini index are also empirically evaluated. We consider several empirical measures to analyse the performance of estimators and confidence intervals, allowing us to quantify the magnitude of the non-response bias problem. We find extremely large biases under certain non-response mechanisms, and this problem gets noticeably worse as the proportion of missing data increases. For a large correlation coefficient between the target and auxiliary variables, the regression imputation method may notably mitigate this bias problem, yielding appropriate mean square errors. We also find that confidence intervals have poor coverage rates when the probability of data being missing is not uniform, and that the regression imputation method substantially improves the handling of this problem as the correlation coefficient increases.

The multi-dimensionality of competitive balance: evidence from European football

PurposeThe purpose of this paper is to address the problem of designing league regulatory mechanisms given the multi-dimensionality of competitive balance and the proliferation of empirical measures.Design/methodology/approachA three-stage approach is adopted. Firstly, a taxonomy of empirical measures of competitive balance is proposed, identifying two fundamental dimensions – win dispersion and performance persistence. Secondly, a simple two-team model of league competitive balance is used to explore the dispersion–persistence relationship. Third, correlation and regression analysis of seven empirical measures of competitive balance for the 18 best-attended top-tier domestic football leagues in Europe over the 10 seasons, 2008–2017, are used to (1) validate the proposed categorisation of empirical measures into two dimensions; and (2) investigate the nature of the dispersion–persistence relationship across leagues.FindingsThe simple model of league competitive balance implies a strong positive dispersion–persistence relationship when persistence effects increase for big-market teams relative to those for the small-market teams. However, the empirical evidence indicates that while leagues such as the Spanish La Liga exhibit a strong positive dispersion–persistence relationship, other leagues show little or no relationship, and some leagues, particularly, the English Premier League and top-tier divisions in Belgium and Netherlands, have a strong negative dispersion–persistence relationship. The key policy implication for leagues is the importance of understanding the direction and impact of dispersion and persistence effects on the demand for league products.Originality/valueThe variability in the strength and direction of the dispersion–persistence relationship across leagues is an important result that undermines the “one-size-fits-all” approach to designing league regulatory mechanisms.

Accounting Conservatism

<p>This thesis provides an in-depth examination of accounting conservatism, which is one of the oldest and most important principles of accounting (Sterling, 1967;Watts, 2003a). Two main questions relating to accounting conservatism are extensively studied in this thesis: (1) How to measure accounting conservatism? (2) Why do firms adopt accounting conservatism? This thesis consists of three main chapters that answer these two questions from three different perspectives. The first chapter studies the existing empirical measures of accounting conservatism from a construct validity perspective and concludes that construct validity of the existing measures is mixed to low. The second chapter examines the validity and bias in the Basu (1997) measure of accounting conservatism - one of the most widely used measure of conservatism in the accounting literature. The second chapter shows, analytically and empirically, that the Basu (1997) measure is biased upwards by the default risk of a firm, and proposes a new measure of conservatism that is free from this bias. This new measure of conservatism is called the "Default-Adjusted-Basu" measure. The third chapter investigates the economic rationale for accounting conservatism, and proposes a signalling theory for accounting conservatism. In a debt market characterized by information asymmetry, a borrower firm's degree of conservatism can serve as a credible signal about that borrower firm's level of operating risk to the lenders in the debt market. Thus, one potential benefit of accounting conservatism is that it can reduce the degree of information asymmetry in the debt market.</p>

Accounting Conservatism

<p>This thesis provides an in-depth examination of accounting conservatism, which is one of the oldest and most important principles of accounting (Sterling, 1967;Watts, 2003a). Two main questions relating to accounting conservatism are extensively studied in this thesis: (1) How to measure accounting conservatism? (2) Why do firms adopt accounting conservatism? This thesis consists of three main chapters that answer these two questions from three different perspectives. The first chapter studies the existing empirical measures of accounting conservatism from a construct validity perspective and concludes that construct validity of the existing measures is mixed to low. The second chapter examines the validity and bias in the Basu (1997) measure of accounting conservatism - one of the most widely used measure of conservatism in the accounting literature. The second chapter shows, analytically and empirically, that the Basu (1997) measure is biased upwards by the default risk of a firm, and proposes a new measure of conservatism that is free from this bias. This new measure of conservatism is called the "Default-Adjusted-Basu" measure. The third chapter investigates the economic rationale for accounting conservatism, and proposes a signalling theory for accounting conservatism. In a debt market characterized by information asymmetry, a borrower firm's degree of conservatism can serve as a credible signal about that borrower firm's level of operating risk to the lenders in the debt market. Thus, one potential benefit of accounting conservatism is that it can reduce the degree of information asymmetry in the debt market.</p>

Profile of Girl Students Studying in Higher Agricultural Education

Present study was conducted during the academic session 2020-21in the College of Agriculture, Central Agricultural University, Imphal, Manipur, India taking 139 girl students randomly studying in B.Sc.(Ag.), M.Sc.(Ag.) and Ph. D. programmes. In this investigation, ''Ex-Post-Facto” research design was used. Socio-personal, communicational-situational, economic and psychological variables were independent variables to study the attitude (dependent variable) of girl students. Different empirical measures and structured schedule were used to know the variables of the study. Scale developed by Heatherton and Polivy [1] for assessment of level of confidence and scale adopted by Ajit [2] and further, used by Hallar (1963) were applied for reckoning the occupational aspirations. Results of the study indicate that majority (77.70%) of the respondents was under 22 years having OGPA between 7.00 to 8.00. Leaving 3.60 per cent of illiterate mothers, all students’ parents were literate. Data also reveals that nearly one third (33.81%) of the students belonged to high family income group whereas, 23.74 per cent belonged to low and 42.45 per cent belonged to medium family income group. Most of them (74.10%) were from OBC, SC/ST categories and nearly two-third of them (63.31%) had medium to very high participation in extra-curricular activities. Majority (64.75%) was from rural background and 54.68% of the respondents used to visit the library either twice or once in a week. More than one third students (35.25%) under study were found using internet at medium level. More than three-fourth (75.54%) of the students’ parents had agriculture, animal husbandry and service as their occupation whereas majority (63.31%) of them was small and marginal farmers. On further analysis, it was seen that 49.64 per cent of the responding students had high level of confidence whereas, majority (79.86%) had medium to high level of occupational aspiration.

How can communication to GPs at hospital discharge be improved? A systems approach

BackgroundPoor communication to GPs at hospital discharge threatens patient safety and continuity of care, with reliance on discharge summaries commonly written by the most junior doctors. Previous quality improvement efforts have largely focused on adherence to standardised templates, with limited success. A lack of understanding has been identified as a cause of the issue’s resistance to decades of improvement work.AimTo understand the system of communication to GPs at hospital discharge, with a view to identifying potential routes to improvement.Design, SettingA qualitative exploration of the secondary-to-primary care communication system surrounding a UK tertiary hospital.MethodA ‘systems approach’, recently defined for the healthcare domain, was used to structure and thematically analyse interviews (n=18) of clinical and administrative staff from both sides of the primary-secondary care interface and a subsequent focus group.ResultsThe largely one-way communication system structure and the low level of hospital stakeholder insight into recipient GP needs emerged as consistent hindrances to system performance. More open lines of communication and shared records might enable greater collaboration to share feedback and resolve informational deficits. Teaching sessions and assessments for medical students and junior doctors led by GPs could help to instil the importance of detail and nuance when using standardised communication templates.ConclusionFacilitating the sharing of performance insights between stakeholder groups emerged as the key theme of how communication might be improved. The empirical measures proposed have the potential to mitigate the safety risks of key barriers to performance, such as patient complexity.

Is vulnerability segmentation at the leaf-stem transition a drought resistance mechanism? A theoretical test with a trait-based model for Neotropical canopy tree species

Key message Leaf-stem vulnerability segmentation predicts lower xylem embolism resistance in leaves than stem. However, although it has been intensively investigated these past decades, the extent to which vulnerability segmentation promotes drought resistance is not well understood. Based on a trait-based model, this study theoretically supports that vulnerability segmentation enhances shoot desiccation time across 18 Neotropical tree species. Context Leaf-stem vulnerability segmentation predicts lower xylem embolism resistance in leaves than stems thereby preserving expensive organs such as branches or the trunk. Although vulnerability segmentation has been intensively investigated these past decades to test its consistency across species, the extent to which vulnerability segmentation promotes drought resistance is not well understood. Aims We investigated the theoretical impact of the degree of vulnerability segmentation on shoot desiccation time estimated with a simple trait-based model. Methods We combined data from 18 tropical rainforest canopy tree species on embolism resistance of stem xylem (flow-centrifugation technique) and leaves (optical visualisation method). Measured water loss under minimum leaf and bark conductance, leaf and stem capacitance, and leaf-to-bark area ratio allowed us to calculate a theoretical shoot desiccation time (tcrit). Results Large degrees of vulnerability segmentation strongly enhanced the theoretical shoot desiccation time, suggesting vulnerability segmentation to be an efficient drought resistance mechanism for half of the studied species. The difference between leaf and bark area, rather than the minimum leaf and bark conductance, determined the drastic reduction of total transpiration by segmentation during severe drought. Conclusion Our study strongly suggests that vulnerability segmentation is an important drought resistance mechanism that should be better taken into account when investigating plant drought resistance and modelling vegetation. We discuss future directions for improving model assumptions with empirical measures, such as changes in total shoot transpiration after leaf xylem embolism.

Household Impacts of Interruption To Electric Power And Water Services

Critical infrastructure systems derive their importance from the societal needs they help meet. Yet the relationship between infrastructure system functioning and societal functioning is not well-understood, nor are the impacts of infrastructure system disruptions on consumers. We develop two empirical measures of societal impacts—willingness to pay (WTP) to avoid service interruptions and a constructed scale of unhappiness, compare them to each other and others from the literature, and use them to examine household impacts of service interruptions. Focusing on household-level societal impacts of electric power and water service interruptions, we use survey-based data from Los Angeles County, USA to fit a random effects within-between model of WTP and an ordinal logit with mixed effects to predict unhappiness, both as a function of infrastructure type, outage duration, and household attributes. Results suggest household impact increases nonlinearly with outage duration, and the impact of electric power disruptions are greater than water supply disruptions. Unhappiness is better able to distinguish the effects of shorter-duration outages than WTP is. Some people experience at least some duration of outage without negative impact. Increased household impact was also associated with using electricity for medical devices or water for work or business, perceived likelihood of an emergency, worry about an emergency, past negative experiences with emergencies, lower level of preparation, less connection to the neighborhood, higher income, being married, being younger, having pets, and having someone with a medical condition in the house. Financial, time/effort, health, and stress concerns all substantially influence the stated level of unhappiness.