Combining domain knowledge and statistical models in time series analysis

This paper describes a new approach to time series modeling that combines subject-matter knowledge of the system dynamics with statistical techniques in time series analysis and regression. Applications to American option pricing and the Canadian lynx data are given to illustrate this approach.Comment: Published at http://dx.doi.org/10.1214/074921706000001049 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

The Effect of the Establishment of the Day Clearing Branch on Trading Costs: A Look at the NYSE In 1920

As a financial institution that clears and settles payments for equity and other securities, a clearinghouse essentially reduces the counterparty risk. It diminishes the risk of one party failing to meet its obligations, and makes markets more efficient through netting. This paper examines the impact of the establishment of the Day Clearing Branch on April 26, 1920, which allowed the NYSE Clearinghouse to net cash values and clear loans, supposedly resulting in savings in banking, time, and labor. The common and preferred equity securities that traded on the NYSE during the year 1920 were analyzed. The effect on bid-ask spreads and volume traded were scrutinized. It was found that these securities had increases in bid-ask spreads and decreases in volume traded, contrary to prior hypotheses

Socioeconomic determinants of multimorbidity: a population-based household survey of Hong Kong Chinese

<b>Introduction</b> Multimorbidity has been well researched in terms of consequences and healthcare implications. Nevertheless, its risk factors and determinants, especially in the Asian context, remain understudied. We tested the hypothesis of a negative relationship between socioeconomic status and multimorbidity, with contextually different patterns from those observed in the West.<p></p> <b>Methods</b> We conducted our study in the general Hong Kong (HK) population. Data on current health conditions, health behaviours, socio-demographic and socioeconomic characteristics was obtained from HK Government’s Thematic Household Survey. 25,780 individuals aged 15 or above were sampled. Binary logistic and negative binomial regression analyses were conducted to identify risk factors for presence of multimorbidity and number of chronic conditions, respectively. Sub-analysis of possible mediation effect through financial burden borne by private housing residents on multimorbidity was also conducted.<p></p> <b>Results</b> Unadjusted and adjusted models showed that being female, being 25 years or above, having an education level of primary schooling or below, having less than HK$15,000 monthly household income, being jobless or retired, and being past daily smoker were significant risk factors for the presence of multimorbidity and increased number of chronic diseases. Living in private housing was significantly associated with higher chance of multimorbidity and increased number of chronic diseases only after adjustments.<p></p> <b>Conclusions</b>Less advantaged people tend to have higher risks of multimorbidity and utilize healthcare from the public sector with poorer primary healthcare experience. Moreover, middle-class people who are not eligible for government subsidized public housing may be of higher risk of multimorbidity due to psychosocial stress from paying for the severely unaffordable private housing

"Factors Influencing the Formation of Union Attitudes"

Underpinned by Fishbein and Ajzen's (1975) theory of reasoned action, this study examined some factors that influence the formation of the attitudinal constructs of affective union commitment, calculative union commitment and union satisfaction among a sample of unionised e1nployees (N=426) in Singapore. Data was obtained with the aid of structured questionnaires. IISREL 7 confirmatory factor analysis provided weak support for the distinctiveness of the three attitudinal constructs. Results of regression analysis revealed that the model explained different amounts of the variance in the attitudinal constructs. Furthermore, although union instrun1entality and union communication there related to all three attitudinal constructs, in general the independent variables where differentially related to the three constructs. For example, union socialisation was related to affective union commitment while procedural justice was related to affective union commitment and union satisfaction, and distributive justice sas related to union satisfaction and calculative union commitment. Limitations of the study, directions for future research and implications of the findings are discusse

The association of types of training and practice settings with doctors’ empathy and patient enablement among patients with chronic illness in Hong Kong

Background: The increase in non-communicable disease (NCD) is becoming a global health problem and there is an increasing need for primary care doctors to look after these patients although whether family doctors are adequately trained and prepared is unknown. Objective: This study aimed to determine if doctors with family medicine (FM) training are associated with enhanced empathy in consultation and enablement for patients with chronic illness as compared to doctors with internal medicine training or without any postgraduate training in different clinic settings. Methods: This was a cross-sectional questionnaire survey using the validated Chinese version of the Consultation and Relational Empathy (CARE) Measure as well as Patient Enablement Instrument (PEI) for evaluation of quality and outcome of care. 14 doctors from hospital specialist clinics (7 with family medicine training, and 7 with internal medicine training) and 13 doctors from primary care clinics (7 with family medicine training, and 6 without specialist training) were recruited. In total, they consulted 823 patients with chronic illness. The CARE Measure and PEI scores were compared amongst doctors in these clinics with different training background: family medicine training, internal medicine training and those without specialist training. Generalized estimation equation (GEE) was used to account for cluster effects of patients nested with doctors. <b>Results</b> Within similar clinic settings, FM trained doctors had higher CARE score than doctors with no FM training. In hospital clinics, the difference of the mean CARE score for doctors who had family medicine training (39.2, SD = 7.04) and internal medicine training (35.5, SD = 8.92) was statistically significant after adjusting for consultation time and gender of the patient. In the community care clinics, the mean CARE score for doctors with family medicine training and those without specialist training were 32.1 (SD = 7.95) and 29.2 (SD = 7.43) respectively, but the difference was not found to be significant. For PEI, patients receiving care from doctors in the hospital clinics scored significantly higher than those in the community clinics, but there was no significant difference in PEI between patients receiving care from doctors with different training backgrounds within similar clinic setting. Conclusion: Family medicine training was associated with higher patient perceived empathy for chronic illness patients in the hospital clinics. Patient enablement appeared to be associated with clinic settings but not doctors’ training background. Training in family medicine and a clinic environment that enables more patient doctor time might help in enhancing doctors’ empathy and enablement for chronic illness patients