Competition for vs. on the rails: a laboratory experiment

Abstract Several European countries and Japan are in various stage

Behavioral Economics and the Public Sector

This thesis consists of four essays dealing with topics that are relevant for the public sector. The essays cover diverse issues of economics partly overlapping with political science. The topics reach from the taxation of labor over monetary policy to preferences over voting institutions. Throughout this thesis it is, in contrast to classical economics, not assumed that humans are necessarily fully rational. Once full rationality is no longer assumed, experiments become an important tool to learn about human behavior. Consequently, most of the work in this thesis makes use of economic experiments

Can environment or allergy explain international variation in prevalence of wheeze in childhood?

Asthma prevalence in children varies substantially around the world, but the contribution of known risk factors to this international variation is uncertain. The International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two studied 8–12 year old children in 30 centres worldwide with parent-completed symptom and risk factor questionnaires and aeroallergen skin prick testing. We used multilevel logistic regression modelling to investigate the effect of adjustment for individual and ecological risk factors on the between-centre variation in prevalence of recent wheeze. Adjustment for single individual-level risk factors changed the centre-level variation from a reduction of up to 8.4% (and 8.5% for atopy) to an increase of up to 6.8%. Modelling the 11 most influential environmental factors among all children simultaneously, the centre-level variation changed little overall (2.4% increase). Modelling only factors that decreased the variance, the 6 most influential factors (synthetic and feather quilt, mother’s smoking, heating stoves, dampness and foam pillows) in combination resulted in a 21% reduction in variance. Ecological (centre-level) risk factors generally explained higher proportions of the variation than did individual risk factors. Single environmental factors and aeroallergen sensitisation measured at the individual (child) level did not explain much of the between-centre variation in wheeze prevalence

Competition For vs. On the Rails: A Laboratory Experiment

Several European countries and Japan are in various stages of privatizing and/or introducing more competition in passenger rail service. This process has been furthered in Europe by a directive from the Commission of the European Communities (1991) requiring member states to separate operations from infrastructure on the books and give international groupings of trains access to their infrastructure. In the Netherlands, the Ministry of Transport, Public Works, and Water Management was assigned responsibility for making a recommendation to Parliament for choosing between competition for the rails and competition on the rails in increasing competition in the supply of passenger rail service. The Ministry commissioned the experiments reported here in order to acquire better understanding of the properties of the two alternative types of competition in the context of a simple stylized rail network. The experimental rail network includes station complementarity and time slot substitutability. It also includes tradeoffs between local and express trains. Competition on the rails involves allocation of rights to use station and time slot routes by price bids in a combinatorial auction. Competition for the rails involves allocation of rights to regional monopolies by fare-structure bids for supplying a pre-specified minimum transport schedule. The experiments include both allocation of rights and scheduling of trains on the network. The two forms of competition are evaluated with various criteria developed by the Ministry, including passenger service and market prices

Overvåking av forurensningsituasjonen i indre Oslofjord 2000 [Fagrådsrapport nr. 85]

Rapporten omhandler resultatene fra undersøkelser foretatt i fjordens vannmasser i år 2000. Fjordens dypvannsfornyelse og oksygenforhold beskrives og overflatevannets kvalitet sommeren 2000 blir bedømt ut fra siktedyp, planteplankton og næringssalter. Fra strandsonen redegjøres for resultatene fra undersøkelser av fem fastsittende tangarters relative forekomst i 1988-20 og dette sammenlignes med tilsvarende undersøkelser de siste 20 årene. Fangster i strandnottrekk blir beskrevet, undersøkelser som går tilbake til 1930-tallet. Observasjoner fra Indre Oslofjords Fiskerlag som er av interesse for fjordmiljøet blir omtalt. Undersøkelser av dyr som lever på og nær bunn (bl.a. reker) fra høsten 2000 blir sammenlignet med tilsvarende observasjoner fra 40 år tilbake. Det gis også et kort sammendrag av en undersøkelse av parasitter og sykdomsfremkallende bakterier på fisk i fjorden. fjorden. Flere av undersøkelsene viser en positiv utvikling i fjorden i tiden etter at rensetiltak er blitt gjennomført. Dette gjelder fjordens overflatelag og strandsone som har blitt klart bedre. I de dypere vannlagene er har det vært en positiv utvikling av dyr som lever på og nær bunn (bl.a. forekomsten av reker i Vestfjorden), sammenfallende med noe bedre oksygenforhold, men for midtre Vestfjord var forholdene i 2000 igjen dårligere. Forekomsten av parasitter og sykdomsfremkallende bakterier på fisk i indre Oslofjord er ikke slik at de utgjør noen som helst fare for konsument eller for fisken selv. konsument eller for fisken selv. Imidlertid er det også mindre positive tegn i dypvannet og dette gjelder spesielt meget dårlige oksygenforhold i Bunnefjorden på 1990-tallet. At forholdene her ikke har blitt bedre skyldes sannsynligvis i stor grad ugunstige klimatiske forhold. Oksygenforbruket i fjorden er mindre i dag enn tidligere (1970-tallet)

UvA-DARE (Digital Academic Repository) Size doesn't matter! Gift exchange in experimental labor markets Size Doesn't Matter! Gift Exchange in Experimental Labor Markets

ABSTRACT We study how the number of traders affects the interaction between a centralized exchange and bilateral negotiations in an experimental labor market with excess supply and incomplete contracts. Our large markets are three times as large as our small markets. In bilateral negotiations firms obtain information about employees' performance in previous jobs. Though market forces put a downward pressure on wages in large markets, reciprocal tendencies do not differ. Hence, the occurrence of bilateral negotiations increases overall efficiency for both market sizes

Surgical skill in bariatric surgery: Does skill in one procedure predict outcomes for another?

BACKGROUND: Recent data establish a strong link between peer video ratings of surgical skill and clinical outcomes with laparoscopic gastric bypass. Whether skill for one bariatric procedure can predict outcomes for another related procedure is unknown. METHODS: Twenty surgeons voluntarily submitted videos of a standard laparoscopic gastric bypass procedure, which was blindly rated by 10 or more peers using a modified version of the Objective Structured Assessment of Technical Skills. Surgeons were divided into quartiles for skill in performing gastric bypass, and within 30 days of sleeve gastrectomy, their outcomes were compared. Multivariate logistic regression analysis was utilized to adjust for patient risk factors. RESULTS: Surgeons with skill ratings in the top (n = 5), middle (n = 10, middle 2 combined), and bottom (n = 5) quartiles for laparoscopic gastric bypass saw similar rates of surgical and medical complications after laparoscopic sleeve gastrectomy (top 5.7%, middle 6.4%, bottom 5.5%, P = .13). Furthermore, surgeons\u27 skill ratings did not correlate with rates of reoperation, readmission, and emergency department visits. Top-rated surgeons had significantly faster operating room times for sleeve gastrectomy (top 76 minutes, middle 90 minutes, bottom 88 minutes; P \u3c .001) and a higher annual volume of bariatric cases per year (top 240, middle 147, bottom 105; P = .001). CONCLUSION: Video ratings of surgical skill with laparoscopic gastric bypass do not predict outcomes of laparoscopic sleeve gastrectomy. Evaluation of surgical skill with one procedure may not apply to other related procedures and may require independent assessment of surgical technical proficiency

Technique or technology? Evaluating leaks after gastric bypass

OBJECTIVE: To assess the relationship between technique and surgical devices on anastomotic and staple-line leaks after laparoscopic Roux-en-Y gastric bypass. BACKGROUND: Leaks after bariatric surgery remain a major source of morbidity and mortality. The association of surgical technique and devices with leaks after gastric bypass is poorly understood. SETTING: Multi-centered study that included teaching and non-teaching hospitals that participate in a statewide consortium for quality improvement using a payer-funded outcome registry. METHODS: We analyzed data from the Michigan Bariatric Surgery Collaborative and performed a case-control study comparing patients who sustained a leak with those who did not after primary laparoscopic Roux-en-Y gastric bypass. A total of 71 (.44%) patients with leaks were identified between January 2007 and December 2011. The leak group was matched 1:2 to a control group (nonleak) based on procedure type, age, body mass index, sex, and the year in which the procedure was performed. Technique-specific case characteristics and device-specific factors were assessed by reviewing operative notes from all primary bariatric procedures in our study population. RESULTS: The rate of leak decreased during the study period, and there was a significant downward trend (slope estimate: -.19961%, P = .0372). After performing multivariate analysis, the type of anastomosis (circular stapler, hand-sewn, or linear stapler) and stapler manufacturer were not associated with leaks. The use of buttressing material was associated with a higher rate of leaks (odds ratio: 8.79 [95% confidence interval: 2.49-31.01], P = .0007), whereas the use of fibrin sealant was associated with a lower rate of leaks (odds ratio .11 [95% confidence interval: .03-.41], P = .0013). These findings could not be explained by differences in measures of surgeon performance. CONCLUSION: Leak rates after laparoscopic gastric bypass have fallen in Michigan despite variations in technique and device utilization. Although the type of anastomosis and stapler manufacturer do not appear to be significantly associated with leaks, it appears that the use of buttressing material was more common in cases in which leaks occurred, whereas the use of fibrin sealant was not. Given the complex interplay of multiple variables that affect surgical outcomes, future studies justifying the benefits of operative devices should be evaluated prospectively in the context of surgeon technique and skill