Approach to Analysis of Self-Selected Interval Data

We analyze an approach to quantitative information elicitation in surveys that includes many currently popular variants as special cases. Rather than asking the individual to state a point estimate or select between given brackets, the individual can self-select any interval of choice. We propose a new estimator for such interval censored data. It can be viewed as an extension of Turnbull's estimator (Turnbull(1976)) for interval censored data. A detailed empirical example is provided, using a survey on the valuation of a public good. We estimate survival functions based on a Weibull and a mixed Weibull/exponential distribution and prove that a consistent maximum likelihood estimator exists and that its accuracy can be consistently estimated by re-sampling methods in these two families of distributions.Interval data; Maximum Likelihood; Turnbull estimator; willingness-to-pay; quantitative elicitation

A note on how to undertake a cost-benefit analysis in monetary and environmental units

In this note we discuss two alternative ways of undertaking a social cost-benefit analysis. One approach is the conventional one where benefits and costs are expressed in monetary units. The other approach uses an environmental asset as the payment vehicle. The properties of the two approaches are discussed and the measurement problems are stressed.Cost-benefit analysis; externalities; choice of numeraire; habitat equivalence analysis; resource equivalency methods

Omreglering så att (nästan) alla blir vinnare

I denna artikel diskuterar vi några av de konflikter som råder kring vattenkraften. En omreglering sådan att i princip alla vinner presenteras. Förslaget tillämpas på Ljusnan där två dammar vid utloppet föreslås bli utrivna och kraftverksägaren kompenseras med en utbyggnad 15 mil uppströms. Lax och andra arter kan då vandra 15 mil uppströms för lek. Vidare förbättras rekreationsmöjligheterna för de kringboende

Paying a Premium for "Green Steel": Paying for an Illusion?

The iron and steel industry generates around 10 % of global greenhouse gas emissions. The bulk of the emissions originates from the iron ore reduction. In this reduction, coal is used as a reagent. Steelmakers could switch to hydrogen-based direct reduction using hydrogen instead of coal as a reagent to reduce iron ore to pig iron. This would eliminate the CO2 emissions from the equivalent process in a traditional blast furnace. However, the process requires massive amounts of electricity. This paper looks at the economics of such a switch to "green steel." We assess a marginal increase in the production of a hypothetical green steelmaker. We also undertake an investment appraisal of a green plant, based on an ongoing installation in Northern Sweden, but also briefly consider a possible/planned investment in the US. This appraisal is complemented by computing the survival function for the net present value in a systematic sensitivity analysis. It seems highly unlikely that a green steel plant can be socially profitable. If the green plant displaces conventional steel produced within the European Union's cap-and-trade system for greenhouse gases, total emissions remain more or less unaffected; permits and emissions are simply reshuffled. Hence, if end-users of green steel pay a premium, they might pay for an illusion

On the social opportunity cost of unemployment

The handling of unemployment is a central issue in cost-benefit analysis. Typically, the shadow price of employing an unemployed is derived by considering a marginal change in the employment constraint faced by an unemployed or rather an underemployed. In contrast, in this paper, we consider the discrete shift from unemployment to (full) employment. The result provides guidance how to estimate the social cost of recruiting otherwise unemployed to a project. It is shown that the social cost is overestimated by using the private reservation wage. The common practice of adding different cost items is shown to be flawed

Behandlingseffekt av glukosamin vid osteoartrit hos hund

Osteoartrit är en progressiv och degenerativ sjukdom där brosket i de synoviala lederna successivt bryts ned. Det är en vanlig åkomma hos våra hundar och symtomen är smärta, hälta och rörelsebegränsning. Den exakta etiologin till osteoartrit är okänd och behandlingen utgörs oftast av smärtstillande och inflammationsdämpande läkemedel. Dessa ger god symtomatisk lindring men kan ha kraftiga bieffekter på framförallt det gastrointestinala området. Som alternativ till de konventionella läkemedlen består behandlingen idag även av preparat som påstås ha såväl symtomatiska som strukturella effekter. Glukosamin är ett substrat i glykosaminoglykansyntesen och anses därmed kunna återuppbygga förlorat broskmatrix genom öka proteoglykansyntesen. Även hyaluronsyrasyntesen tros kunna öka vid tillsats av glukosamin, vilket ger en bättre viskositet och därmed stötdämpning i leden. En glukosaminmedierad minskning av mängden matrixmetalloproteinaser och inflammatoriska cytokiner som frisätts vid osteoartrit uppges hämma broskdegraderingen. Att glukosamin dessutom uppges ge mycket få och milda bieffekter gör att många veterinärer idag rekommenderar dessa preparat vid behandling av ledproblem hos hund. Problemet är att det finns få tillförlitliga studier på de exakta verkningsmekanismerna och effektiviteten av glukosaminbehandling hos hund. Bland de försök som gjorts skiljer sig resultaten dessutom nämnvärt

Dödsorsaker och nedärvningsmönster av dilaterad kardiomyopati hos grand danois

Dilaterad kardiomyopati (DCM) är en allvarlig hjärtsjukdom som drabbar flera hundraser, men är vanligast bland de stora raserna. Sjukdomen drabbar hjärtmuskulaturen varpå hjärtats kontraktionsförmåga försämras. Detta leder på sikt till volymsöverbelastning, dilatation av hjärtats hålrum och kliniska tecken på hjärtsvikt. DCM är en viktig dödsorsak hos grand danois och den höga prevalensen tyder på att det finns en genetisk faktor bakom utvecklandet av sjukdom. Resultat från flera studier där ärftligheten studerats, tyder på en autosomal dominant nedärvning, men även x-bunden recessiv nedärvning har föreslagits. Syftet med denna studie var att, utifrån en studiepopulation bestående av renrasiga grand danois hemmahörande i Sverige och Norge, undersöka de vanligaste dödsorsakerna, och om det fanns någon signifikant skillnad i medeldödsålder mellan hundar som dött i DCM och hundar som dött av övriga orsaker. Vidare undersöktes om någon signifikant överrepresentation kunde fastställas i prevalens av sjukdomen hos något av könen, samt om medeldödsåldern mellan tikar och hanhundar som drabbats av DCM skiljde sig signifikant. Information om studiepopulationens hälsoläge avseende DCM registrerades i syfte att användas inom ett EU-finansierat molekylärgenetiskt forskningsprojekt (LUPA) som arbetar med att fastställa den genetiska bakgrunden till ett antal sjukdomar hos hund och däribland DCM. Då arvbarheten är av stor betydelse för denna forskning undersöktes studiepopulationen även avseende nedärvningsmönster. Studiepopulationen bestod av 185 grand danois vars kliniska status följdes upp genom telefonintervjuer med ägare eller uppfödare. Hundarna delades sedan in enligt eventuell dödsorsak, kön och medeldödsålder. Resultatet av studien visade att de vanligaste dödsorsakerna var DCM, avlivad av annan orsak, tumörsjukdomar och neurologiska störningar. Ingen signifikant skillnad kunde påvisas i medellivslängd mellan hundar som dött i DCM och hundar som dött av övriga orsaker. Hanhundar visade sig vara signifikant överrepresenterade avseende förekomst av DCM, men ingen signifikant skillnad i dödsålder mellan tikar och hanhundar som drabbats av DCM kunde påvisas. Analyser av sjukdomsfördelningen inom familjer tyder på en stark genetisk faktor bakom utvecklande av DCM, och det mest sannolika nedärvningsmönstret i denna studie var autosomal dominant nedärvning med ofullständig penetrans.Dilated cardiomyopathy (DCM) is a serious heart disease with the highest prevalence found in large to giant sized breeds. The disease affects the myocardium, which leads to reduced myocardial contractility. In turn this leads to volume overload, dilatation of cardiac chambers and clinical signs of congestive heart failure (CHF). DCM is an important cause of death in Great Danes, and the high prevalence indicates a genetic background. The inheritance of DCM has been investigated in both Great Danes and several other breeds, and most studies indicate that the disease is inherited as an autosomal dominant trait, although an x-linked recessive pattern has also been suggested. This study was undertaken to investigate the most common causes of death of a study population consisting of pure-bred Great Danes living in Sweden and Norway, and to evaluate if there was any significant difference in mean age of death between dogs that died from DCM and dogs that died from other causes. We also aimed to investigate if there was any significant overrepresentation in prevalence in male compared to female dogs affected by DCM, and if there was any significant difference in mean age of death between female and male dogs that had died from DCM. The information of the study population was obtained through telephone interviews with owners and breeders. The dogs were then classified based on cause of death, gender and mean age of death. The information concerning the health status of the study population will be used in a European molecular genetic research project (LUPA). This project aims to unravel the genetic background of a number of diseases in the dog, including DCM. Because the mode of inheritance is of great importance for this type of research, the study population was also investigated with regards to inheritance pattern. The results showed that the most common causes of death were DCM, euthanized for other reasons, neoplastic diseases and neurological disturbances. No significant difference in mean age of death could be found between dogs that had died from DCM and dogs that died from other causes. Males were significantly overrepresented regarding prevalence of DCM but there was no significant gender difference in mean age of death in dogs affected by DCM. Pedigree analyses showed that the development of the disease had a strong genetic influence and that the inheritance pattern was consistent with an autosomal dominant trait with incomplete penetration

Quantile regression with interval-censored data in questionnaire-based studies

Interval-censored data can arise in questionnaire-based studies when the respondent gives an answer in the form of an interval without having pre-specified ranges. Such data are called self-selected interval data. In this case, the assumption of independent censoring is not fulfilled, and therefore the ordinary methods for interval-censored data are not suitable. This paper explores a quantile regression model for self-selected interval data and suggests an estimator based on estimating equations. The consistency of the estimator is shown. Bootstrap procedures for constructing confidence intervals are considered. A simulation study indicates satisfactory performance of the proposed methods. An application to data concerning price estimates is presented

Impact of blood tube additives and timing of sampling on blood taurine concentrations in clinically healthy dogs

Introduction: Dilated cardiomyopathy can be associated with taurine deficiency in dogs. Blood taurine concentrations can be analyzed in whole blood (WB) and plasma. The study objectives were to investigate agreement between taurine concentrations measured in WB, heparin plasma, and EDTA plasma, deter-mine intraindividual variation in healthy dogs, and evaluate if time from feeding to sampling impacts concentrations. Animals: 10 English Cocker spaniels and 10 dogs of various breeds. Materials and methods: Dogs were fasted 12 h prior to initial blood sampling, and the blood was collected at five occasions over 8 h. Food was offered immediately after first and 1 h after fourth sampling time point. Results: Agreement between taurine concentrations in EDTA plasma and hepari-nized plasma was good (mean difference 4.5 nmol/mL, 95% confidence interval (CI) 36.8-45.8 nmol/mL). WB concentrations were systematically higher than EDTA and heparin plasma concentrations (mean difference 132.7 nmol/mL, 95% CI 23.6-241.8 nmol/mL, and 127.6 nmol/mL, 95% CI 28.6-226.6 nmol/mL, respectively, all P < 0.001). Intraindividual daily variations in taurine concentration were seen in all additives, with largest variations in plasma (P < 0.001). Taurine concentration in heparinized plasma was higher at first and fifth sampling time points compared to the fourth (P 1/4 0.014). Discussion: Agreement was found between taurine concentrations measured in dif-ferent additives, with expected higher concentration in WB than plasma. Taurine concentrations measured in heparinized plasma varied with sampling time point. Intraindividual daily variations were observed in all additives, but mainly in plasma samples. Conclusion: Taurine concentrations in dogs with suspected deficiency should be in-terpreted with caution. 2022 The Authors. Published by Elsevier B.V

Models predicting the growth response to growth hormone treatment in short children independent of GH status, birth size and gestational age

<p>Abstract</p> <p>Background</p> <p>Mathematical models can be used to predict individual growth responses to growth hormone (GH) therapy. The aim of this study was to construct and validate high-precision models to predict the growth response to GH treatment of short children, independent of their GH status, birth size and gestational age. As the GH doses are included, these models can be used to individualize treatment.</p> <p>Methods</p> <p>Growth data from 415 short prepubertal children were used to construct models for predicting the growth response during the first years of GH therapy. The performance of the models was validated with data from a separate cohort of 112 children using the same inclusion criteria.</p> <p>Results</p> <p>Using only auxological data, the model had a standard error of the residuals (SD_res), of 0.23 SDS. The model was improved when endocrine data (GH_maxprofile, IGF-I and leptin) collected before starting GH treatment were included. Inclusion of these data resulted in a decrease of the SD_resto 0.15 SDS (corresponding to 1.1 cm in a 3-year-old child and 1.6 cm in a 7-year old). Validation of these models with a separate cohort, showed similar SD_resfor both types of models. Preterm children were not included in the Model group, but predictions for this group were within the expected range.</p> <p>Conclusion</p> <p>These prediction models can with high accuracy be used to identify short children who will benefit from GH treatment. They are clinically useful as they are constructed using data from short children with a broad range of GH secretory status, birth size and gestational age.</p