Selection Bias in Comparative Research: The Case of Incomplete Data Sets

Selection bias is an important but often neglected problem incomparative research. While comparative case studies pay someattention to this problem, this is less the case in broadercross-national studies, where this problem may appear throughthe way the data used are generated. The article discusses threeexamples: studies of the success of newly formed political parties,research on protest events, and recent work on ethnic conflict.In all cases the data at hand are likely to be afflicted byselection bias. Failing to take into consideration this problemleads to serious biases in the estimation of simple relationships.Empirical examples illustrate a possible solution (a variationof a Tobit model) to the problems in these cases. The articlealso discusses results of Monte Carlo simulations, illustratingunder what conditions the proposed estimation procedures leadto improved results.     

Glycine toxicity and unexpected intra-operative death

A rare complication of the use of glycine irrigation fluid during prostatic surgery in a 69-year-old man is described. Following cystolithopexy and transurethral resection of the prostate for benign prostatomegaly, abdominal distension developed with increasing ventilatory pressures. Despite retroperitoneal fluid evacuation at subsequent urgent laparotomy, cardiac arrest occurred that was not amenable to resuscitation. At autopsy a traumatic defect in the posterior bladder wall filled with calculus debris was confirmed that did not communicate with the peritoneal cavity. Hyponatremia with markedly elevated levels of blood, urine, and body fluid glycine were demonstrated. Death was, therefore, attributed to glycine toxicity following tracking of glycine through a surgical defect in the posterior bladder wall. Careful dissection of surgical sites is required in such cases to demonstrate any additional trauma that may be associated with the fatal episode. Analysis of body fluids for glycine and electrolytes is also necessary to assist in the determination of possible mechanisms of death.     

Experience with urine drug testing by the Correctional Service of Canada

The Correctional Service of Canada implemented a urine drug-screening program over 10 years ago. The objective of this report is to describe the program and drug test results in this program for 1999. Offenders in Canadian federal correctional institutions and those living in the community on conditional release were subject to urine drug testing. Urine specimens were collected at correctional facilities and shipped by courier to MAXXAM Analytics Inc. laboratory. All urine specimens were analyzed for amphetamines, cannabinoids, cocaine metabolite (benzoylecgonine), opiates, phencyclidine, benzodiazepines, methyl phenidate, meperidine, pentazocine and fluoxetine by immunoassay screening (homogeneous EIA and ELISA assays) followed by GC-MS confirmation. Ethyl alcohol was analyzed when specifically requested. Alternative screening and confirmation methods with lower cut-off values were used, whenever urine specimens were dilute (creatinine <20mg/dl and specific gravity 相似文献   

The microeconomic voter

In the United States, aggregate and individual level studies of economic voting for the Congress have produced contradictory findings. The same is true for models of economic voting for the Australian Parliament. This paper presents data taken from a series of individual level studies which show that voters' attitudes towards fiscal and microeconomic issues have been better predictors of the vote for the Australian House of Representatives over the last four elections than their attitudes towards macroeconomic issues. This finding suggests that the cause of the inconsistency between aggregate and individual level models of voting may be that aggregate models of economic voting which include only macroeconomic variables are inadequately specified, since they do not take broader aspects of the economy into account.     

Politische Orientierungen gewerkschaftlich organisierter Arbeiter- und Mittelschichten in der Schweiz

Das Thema dieser Studie sind die politischen Einstellungen von ge-werkschaftlich organisierten Arbeitnehmerinnen und Arbeitnehmern in der Schweiz. Anhand von Daten einer repräsentativen Befragung von Mitgliedern von drei schweizerischen Gewerkschaften (GBI, SMUV, VPOD) und eines Angestelltenverbandes (VSAM) wird im folgenden dokumentiert, dass die "traditionelle" Arbeiterschicht, die "sozialkulturellen Spezialisten" sowie die "Technokraten" und "Manager" jeweils unterschiedliche politische Orientierungen vertreten. Während die Arbeiter für "klassisch" linke, sozialdemokratische und eher materialistische politische Positionen einstehen, sind die gewerkschaftlich organisierten "sozialkulturellen Spezialisten" in der Mittelschicht deutlich linker und postmaterialistischer und die ebenfalls der Mittelschicht zuzurechnenden "Technokraten" und "Manager" eher bürgerlich und materialistischer eingestellt. Insgesamt lassen sich weder für die These einer Entpolitisierung noch für die These einer Konvergenz der politischen Orientierungen eindeutige Hinweise finden. Vielmehr ist die gewerkschaftlich organisierte Arbeitnehmerschaft in der Schweiz politisch heterogen. Diese Heterogenität wiederum reduziert die Macht und Einflusschancen der schweizerischen Gewerkschaftsbewegung.     

Use of subpopulation data in Australian forensic DNA casework

DNA profiling evidence presented in court should be accompanied by a reliable estimate of its evidential weight. In calculating such statistics, allele frequencies from commonly employed autosomal microsatellite loci are required. These allele frequencies should be collected at a level that appropriately represents the genetic diversity that exists in the population. Typically this occurs at broadly defined bio-geographic categories, such as Caucasian or Asian. Datasets are commonly administered at the jurisdictional level. This paper focuses on Australian jurisdictions and assesses whether this current practice is appropriate for Aboriginal Australian and Caucasian populations alike. In keeping with other studies we observe negligible differences between Caucasian populations within Australia when segregated geographically. However segregation of Aboriginal Australian population data along contemporary State and Territory lines appears to mask the diversity that exists within this subpopulation. For this reason datasets collated along more traditional lines may be more appropriate, particularly to distinguish the most genetically differentiated populations residing in the north of the continent.