The Welfare Cost of Imperfect Competition and Distortionary Taxation

The welfare cost of imperfect competition in the product and labor market as well as distortionary taxation is quantified in a dynamic general equilibrium model parameterized to fit the U.S. economy. We find that the welfare cost of imperfect competition in the product market is 35.74 percent while it is 0.66 percent in the labor market, taking the transition from the distorted to the optimal steady state into account. If we also take into account that the U.S. economy is characterized by distortionary taxation the welfare cost in the product market increases to 48.26 percent and 4.70 percent in the labor market

Supporting real-time data traffic in safety-critical, vehicle-to-infrastructure communication

communicatio

Inflation, Markups and Monetary Policy

The correlation between persistent changes in the markup in one sector of an economy and the inflation rate is quantified in a 2-sector dynamic general equilibrium model. How this relationship is affected by monetary policy is also studied. We find that the correlation is in general positive under an exogenous money growth rule as well as under an inflation targeting rule. That is, a decrease of the markup leads to a decrease in the CPI-inflation rate. However, if inflation is measured by an optimal price index that also includes the wage rate the correlation is slightly negative. That is, a decrease in the markup leads to higher inflation rates. This is due to higher wage rates. The correlation is sensitive to whether the policy rule includes an output term. If monetary policy accommodates output strongly the correlation is negative. A decrease in the markup leads to higher inflation rates, as measured by both the CPI and the optimal price index

Exploring Sexual Harassment in the Police Force in Japan: A Comparative Study between Japan and the United States

Att företag i Sverige påverkas av den enorma tillväxt som sker i Kina och att utvecklingen i Kina dessutom påverkas av hur svenska företag agerar borde, efter all uppmärksamhet i media, vara uppenbart. Då bilden som presenteras i media ofta är onyanserad har Teknikföretagen gett oss i uppdrag att göra en kartläggning av teknikföretags relationer med Kina. Syftet är att undersöka i vilken omfattning och varför företagen har dessa relationer samt hur företagen påverkas av dem. Undersökningens omfattning har begränsats genom att en geografisk avgränsning till Östergötland gjorts. Det visar sig i studien att de undersökta företagen har betydande kontakter med Kina, det är vanligare och viktigare med import än export och det är relativt många som har någon grad av högre engagemang där. – Varför har då dessa företag kontakter med Kina? I studien framkommer att det finns två övergripande anledningar till att företagen etablerar kontakt med Kina. Det första är prispress och det andra är kundnärhet. Företag som är i Kina på grund av prispressen i deras branscher har ofta outsourcat delar av sin produktion till Kina eller väljer att köpa av kinesiska leverantörer istället för av svenska. I studien visar det sig att detta är något som även små företag utan någon större internationell erfarenhet klarar. De företag som svarar på behovet av kundnärhet gör det istället i stor utsträckning genom att etablera egna produktionsanläggningar i Kina eftersom många av deras kunder redan finns där. För detta krävs betydligt större resurser än för att outsourca och många av företagen upplever en begränsning i form av bristande ledningskapacitet. Vi ser även att företagens motiv förändras över tiden. – Hur påverkas då den svenska verksamheten av företagens relationer med Kina? Många av företagen som outsourcat produktion går mot att sysselsätta sig mer med konstruktion, inköp, service och underhåll än produktion, vilket förvisso gör att företagen utför mer kvalificerade uppgifter och försäkrar sig om att på kort sikt inte slås ut av prispressen. Däremot riskerar de att på sikt bli av med nödvändig kompetens och servicekapacitet på grund av att investeringarna blir lägre och nyckelpersonal går i pension. De företag som istället satsar i Kina för att sälja där påverkas positivt även i Sverige. Det krävs ofta att verksamheten i Sverige expanderar för att kunna hantera verksamheten i Kina. Att ha närvaro på flera marknader innebär också att vara mindre känslig för konjunktursvängningar. För att komma fram till undersökningens resultat har en inledande litteraturstudie kompletterats med intervjuer av personer med relevant kunskap om ämnet. Därefter genomfördes en enkätundersökning vars svar analyserades statistiskt. Dessa resultat kompletterades med fallstudier av flera av de undersökta företagen. Undersökningen avslutades med besök hos några av de undersökta företagens anläggningar i Kina för att verifiera undersökningens resultat.Because of the media coverage it is probably clear to all that companies in Sweden are affected by the astonishing growth currently at hand in China as well as the development in China is affected by actions taken by Swedish companies. To get a more complete understanding of this development the Swedish engineering association has asked us to investigate the relations between Swedish engineering companies and China. The purpose is to examine to what extent and why these relations exist and how they affect the companies. The study has been limited to study only companies in Östergötland. In the study it is shown that the investigated companies do have business relations with China, importing is more important than exporting and quite a few companies have more advanced business engagements in China. – Why do these companies have contacts with China? This study shows two basic reasons behind these contacts. The first is a pressure on prices and the second is proximity to customers. The companies that are in China to lower their prices have to a large extent outsourced production to Chinese companies or have switched from western to Chinese suppliers. This is an action that is feasible even for small companies without previous international experience. On the other hand, companies that are in China to achieve proximity to their clients tend to set up production plants in China as many of their customers have already done so. To do this requires far more resources than outsourcing and many companies experience limitations in their management capacity. We also see that the companies’ motives often change over time. – How do these contacts affect the Swedish companies? Many of the companies who have outsourced parts of their production tend to be more focused on services, which does enable them to perform more advanced processes and saves them from becoming extinct due to increased price competition. In the long run however, they risk losing necessary competence and capacity as they lower their investments and their key personnel retire. Companies that are in China in order to sell in China are affected positively in Sweden as well. It is often necessary to expand business in Sweden in order to manage what is done in China and the presence in many markets make the companies’ orders less volatile. To achieve the results of this investigation we started by studying existing literature and conducting a series of interviews with people with relevant knowledge regarding the subject. Based on this information we conducted a survey that was statistically analyzed. These results where afterwards completed with case studies of several of the investigated companies. The investigation was finalized with a visit at some of the Swedish companies’ production plants in China in order for us to verify our conclusions

Do Higher Wages Cause Inflation?

Much empirical evidence suggests that wage increases do not lead to inflation. This paper demonstrates that a 2-sector dynamic general equilibrium model calibrated to the U.S. economy is able to explain this evidence. We quantify the effect of an increased wage-markup on the inflation rate in both the goods sector and the service sector. The mechanisms we emphasize and quantify are changes in relative prices and monetary policy. We find that our model is successful in explaining the empirical evidence. Quantitatively, the relative price effect is more important than monetary policy in mitigating the effect of higher wage-markups

Wired and Wireless Reliable Real-Time Communication in Industrial Systems

In modern factory automation systems, data communication plays a vital role. Different nodes like control systems, sensors and actuators can communicate over a wireless or wired industrial network. The data traffic generated is often scheduled for periodic transmission, where each single message or packet must arrive in time. For this real-time communication, methods have been developed to support communication services with a guaranteed throughput and delay bound for such periodic traffic, but merely under the assumption of error-free communication. However, the possibility for errors in the transmission still exists due to, e.g. noise or interference. A node receiving sensor values from a sensor in the system might then be forced to rely upon an older sensor value from the latest period, possibly leading to inaccuracies in control loops which can compromise the functioning of the system. In safety-critical systems, redundant networks or communication channels are frequently added to cope with errors, leading to more expensive systems. In this chapter, we will describe an alternative approach where erroneous data packets are retransmitted in a way that does not jeopardise any earlier stated real-time guarantees for ordinary transmissions. Using our framework, the reliability of real-time communication can be increased in a more cost-efficient way. We describe in this chapter an overview of our framework for reliable real-time communication, while details of our approach can be found in our earlier publications. In the light of the emerging use of wireless communication, the framework proves to be especially useful due to the high bit error rate inherent to the wireless medium. However, the framework is naturally also attractive for wired communication systems

Potential output in DSGE models

In view of the increasing use of Dynamic Stochastic General Equilibrium (DSGE) models in the macroeconomic projections and the policy process, this paper examines, both conceptually and empirically, alternative notions of potential output within DSGE models. Furthermore, it provides historical estimates of potential output/output gaps on the basis of selected DSGE models developed by the European System of Central Banks’ staff. These estimates are compared to the corresponding estimates obtained applying more traditional methods. Finally, the paper assesses the usefulness of the DSGE model-based output gaps for gauging inflationary pressures. JEL Classification: E32, E37, E52monetary policy, potential output, simulation and forecasting models

Potential Output in DSGE Models

In view of the increasing use of Dynamic Stochastic General Equilibrium (DSGE) models in the macroeconomic projections and the policy process, this paper examines, both conceptually and empirically, alternative notions of potential output within DSGE models. Furthermore, it provides historical estimates of potential output/output gaps on the basis of selected DSGE models developed by the European System of Central Banks’ staff. These estimates are compared to the corresponding estimates obtained applying more traditional methods. Finally, the paper assesses the usefulness of the DSGE model-based output gaps for gauging inflationary pressures.potential output, simulation and forecasting models, monetary policy

Methodological aspects on carotid artery intervention

In Sweden, approximately 25000 patients suffer a cerebral infarction (stroke) annually. Stroke ranks as the third-leading cause of death, and is the leading cause of functional impairment. Carotid artery stenosis accounts for approximately 15% of all strokes and almost all of these are theoretically preventable. There are two conceptually different invasive methods used to treat carotid stenosis: carotid artery stenting (CAS) and carotid endarterectomy (CEA). There are various aspects of these treatments that remain to be evaluated in order to minimize the risks of poor outcome, namely: any differences in short-term and long-term outcomes after CEA or CAS, the potential risks of CAS early after a previous transient ischaemic attack (TIA)/stroke, and the methods to indicate the need of shunting during CEA. Furthermore, since data from randomised controlled trials (RCTs) are often from specialized high volume centres with selected patients, it is important to evaluate population-based results after CAS and CEA. The overall aim of this thesis was to investigate aspects of invasive treatment of carotid artery stenosis, in particular the outcome following endovascular treatment (CAS), and the efficacy of near-infrared spectroscopy in predicting selective shunt use during CEA. The outcome after endovascular treatment was investigated in three cohort studies (study I, II, and III). In study I, we analysed Swedish national short-term results of CAS and CEA and compared a high-volume centre with national results for CAS. In study II we evaluated the procedural risk of CAS, in relation to time from previous TIA /stroke. Study III assessed the long-term population-based outcomes after CAS as compared to CEA. In study IV, a multi- centre diagnostic study, we evaluated the ability of near-infrared spectroscopy (NIRS) to pre- dict cerebral ischaemia during CEA. Study I was a retrospective single-centre review of all consecutive patients treated with CAS at Södersjukhuset between 2004-2011. These results were compared to data from the Swedish national registry for vascular surgery (Swedvasc), where data from all patients treated with CAS or CEA during the same period was extracted. We found that the Swedish national results for CAS were inferior to CEA, but also that it was possible to achieve acceptable results with CAS in a high volume centre. During the study period 464 CAS procedures were performed in Sweden, with 208 of them performed at Södersjukhuset. The stroke and death rate at 30 days among patients in Sweden (Södersjukhuset excluded) was 7.4%. In Södersjukhuset, the stroke and death rate was 2.9%. The results for CAS on a national basis improved over time, the stroke and death rate during the first half of the period was 6.4%, compared to 3.6% in the sec- ond part of the study period, which was probably due to the learning curve for the procedure. In study II, all CAS performed for symptomatic carotid stenosis between 2005-2014, were included in a retrospective analysis. Study II revealed that it was safe to perform CAS early (within 1 week), following a TIA/stroke. The stroke and death rate for patient treated within 7 days from neurologic symptom was 4.1%, compared to 6.3% between day 8-14, 4.8% between day 15-28, and 3.6% between days 29-180. The long-term results after CAS in Sweden were examined in study III. In this study, all primary CAS procedures registered in Swedvasc were included (all reoperations were excluded). We compared 409 CAS patients to a control group treated with CEA. The control group was matched with respect to known confounding factors. Postoperative stroke was identified by cross matching the cohort with the In-patient registry. Median follow-up time was 4.1 years, and follow-up data was almost complete. By using Cox regression, we found a substantial (59%) increased risk for late(>30 days) stroke or death for patients treated with CAS compared to CEA. This increased risk was mainly due to an increased risk of ipsilateral stroke during long-term follow-up. In study IV, we have shown that near-infrared spectroscopy has a high sensitivity and accept- able specificity to predict cerebral ischemia during CEA. When a cut-off point of 9% relative decrease in regional SO2 during carotid clamping was chosen, the sensitivity for detecting cerebral ischemia was 95%, and the specificity 81%. This was clearly superior to the conventional and widespread technique of measuring, “stump pressure”. In conclusion, the national population-based results for CAS were inferior to CEA, both short- and long-term. The short-term results after CAS in Sweden have improved over time, and acceptable results can be achieved in high volume centres. If CAS is performed due to symptomatic stenosis it could be performed early after onset of neurologic symptoms. Near-infrared spectroscopy is a reliable method for selective shunting during CEA and superior to stump pressure

Application of Photoluminescent Measurement Techniques for Quantitative Assessment of Turbine Film Cooling

Reduction of the specific fuel consumption of gas turbines can be achieved by maximizing the turbine inlet temperature. However, this requires a detailed understanding of the cooling performance in order to ensure safe and economical operation of the engine. This is because the resulting temperature distributions in the blade walls dictate the thermal stresses and life-time of the hot section of the engine. Film cooling performance depends on a large number of parameters including turbulence making it complex to predict numerically. Moreover, the harsh flow conditions found in turbines situated directly downstream of the combustion chamber makes it difficult to obtain high resolution measurements of the relevant quantities. Therefore, simplified experiments are employed in order to simulate the engine situation by matching the most important flow similarity parameters. More specifically, the large difference in temperature between hot-gas and cooling air leads to considerable difference in density between the film cooling jets and hot-gas. This can be simulated at ambient temperatures by injecting a heavy foreign gas into a less dense main-flow of air. This thesis aims at demonstrating the applicability of photoluminescent paints as sensing element for film cooling measurements. When this type of sensor is excited by ultraviolet light, the photoluminescent process leads to the emission of red-shifted light. The luminescence depends on oxygen pressure as well as temperature at the coating surface. A commercially available Pressure Sensitive Paint (PSP) is chosen for experimental characterization of the two fundamental quantities of film cooling: Adiabatic film cooling effectiveness Heat transfer coefficients The adiabatic film cooling effectiveness is a measure of the mixing between coolant and mainflow. This quantity corresponds to concentration of gas species according to the analogy between heat and mass transfer. An oxygen-free coolant acts as tracer gas as it dilutes the oxygen of the main-flow, allowing for detailed measurements of the cooling gas concentration with PSP. The corresponding convective heat transfer coefficient is measured by imposing step changes in heat flux and tracing the transient temperature response of the wall. For this purpose, the same PSP-sensor is employed for thermography measurements by taking advantage of the inherent temperature sensitivity of this technology. An engine-realistic test case illustrates the capability of the technique under complex flow conditions. It allows to demonstrate that measurements with high spatial resolution can be obtained over large portions of the surface within a short period of time. It turns out that the combination of oxygen pressure and temperature sensors, in the form of photoluminescent paint, is particularly advantageous in compressible flow experiments with moderate heat transfer at the wall. Another important advantage of the technique is the possibility to separate the adiabatic film cooling effectiveness from the wall heat transfer effects, without applying another coating for separate experiments. This ensures high geometrical tolerance of the small-scale cooling holes of the experimental models. However, the technique is limited by the maximum applicable temperature of the photoluminescent system making it first of all suitable for cold-flow measurements. While both pressure and temperature sensitive paints have previously been employed in film cooling studies, the proposed combination of those techniques is unique in that it allows for simultaneous, yet decoupled measurement of the two fundamental quantities in film cooling. In the present thesis, it is shown that the application of the presented technique allows to validate numerical flow models. Furthermore, conclusions can be transferred to the modelling of real engines in the form of technology trends. Ultimately, this allows to optimize film cooling performance and reduce the fuel consumption of gas turbines