Incomplete cost pass-through under deep habits

A number of empirical studies document that marginal cost shocks are not fully passed through to prices at the firm level and that prices are substantially less volatile than costs. We show that in the relative-deep-habits model of Ravn, Schmitt-Grohe, and Uribe (2006), firm-specific marginal cost shocks are not fully passed through to product prices. That is, in response to a firm-specific increase in marginal costs, prices rise, but by less than marginal costs leading to a decline in the firm-specific markup of prices over marginal costs. Pass-through is predicted to be even lower when shocks to marginal costs are anticipated by firms. In our model, unanticipated firm-specific cost shocks lead to incomplete pass-through (or a decline in markups) of about 20 percent and anticipated cost shocks are associated with incomplete pass-through of about 50 percent. The model predicts that cost pass-through is increasing in the persistence of marginal cost shocks and U-shaped in the strength of habits. The relative-deep-habits model implies that conditional on marginal cost disturbances, prices are less volatile than marginal costs

The macroeconomics of subsistence points

This paper explores the macroeconomic consequences of preferences displaying a subsistence point. It departs from the existing related literature by assuming that subsistence points are specific to each variety of goods rather than to the composite consumption good. We show that this simple feature makes the price elasticity of demand for individual goods procyclical. As a result, markups behave countercyclically in equilibrium. This implication is in line with the available empirical evidence

Combinatorial classification of quantum lens spaces

We answer the question of how large the dimension of a quantum lens space must be, compared to the primary parameter $r$, for the isomorphism class to depend on the secondary parameters. Since classification results in C*-algebra theory reduces this question to one concerning a certain kind of $SL$-equivalence of integer matrices of a special form, our approach is entirely combinatorial and based on the counting of certain paths in the graphs shown by Hong and Szyma\'nski to describe the quantum lens spaces.Comment: 27 pages, 2 figure

On Adjusting the H-P Filter for the Frequency of Observations

This paper studies how the HP-Filter should be adjusted, when changing the frequency of observations. The usual choices in the literature are to adjust the smoothing parameter by multiplying it with either the square of the observation frequency ratios or simply with the observation frequency. In contrast, the paper recommends to adjust the filter parameter by multiplying it with the fourth power of the observation frequency ratios. Based on this suggestion, some well-known comparisons of business cycles moments across countries and time periods are recomputed. In particular, we overturn a finding by Backus and Kehoe (1992) on the historical changes in output volatility and return instead to older conventional wisdom (Baily, 1978, Lucas, 1977): based on the new HP-Filter adjustment rule, output volatility turns out to have decreased after the Second World War.

JUMPING STRATEGIES IN A VOLLEYBALL AND A BALLET SPECIFIC JUMP

INTRODUCTION The performance of a maximal vertical jump fram a static preparatory position (SQJ) or starting with a counter movement (CMJ) implies transformation of rotation about the hip, knee and ankle joints to a maximal translatory movement. Different strategies have been proposed for this transformation. Previously both sequential and simullaneous strategies have been proposed as optimal for maximal vertical jumping (1 & 2). The purpose of this study was to analyze ]umping strategies in a sport and dance specific maximal vertical jump. The hypothesis was that the technical demands of the Jumps would preset the strategy. Six male subjects participated in the study three professional ballet dancers and three elite volleyball players. In the ballet specific jump (BSJ) the legs were outward rotated, one foot was placed in front of and close to the other foot and the upper body kept upright. Three elite volleyball players performed the jump used for the smash (VSJ) including a three step preliminary run up and a farcefull arm swing. Afterwards all six subjects performed SQJ and CMJ. The ]umps were recorded on high speed film (500Hz) combined with registrations trom an AMTI force platform and EMG recordings from the major lower extremity muscles Net joint moments and joint work ware calculated by inverse dynamics. The strategy of the jumps was determined on the basis of angular kinematics and the pattern of nel joint moments of the two dominant joints RESULTS For BSJ the jumping height (h) was 0.22O.28m.The war!< contribution from the knee and ankle joint were 50-70% and 47-63% of the total work respectively while the work at the hip joint showed a negative contribution of 13-17% caused by a net hip flexor moment. Because of the specific ballet position the hip extension took place in the frontal plane and mgluteus maximus could not contribute to the extension. The concentric activity in mrectus femoris could partly explain the hip flexor moment. The knee and ankle joint initiated the extension phase simultaneously and the net joint moments peaked also simultaneously Therefore, the strategy could be defined as simultaneous. For VSJ h was 0.310.45m. The work contribution fram the knee and hip joints were 22-60% and 35-62% of the total work respectively. The hip joint began the extension phase before the body center of mass had reached its lowest position (sn The knee extension began 40-100ms after s.j. The peaks of the net joint moments of the hip and knee showed a similar pattern. Accordingly, the strategy could be defined as sequentiaL The sequential joint extension could partly be explained by the forcefull armswing pressing down and giving negative momentum in the downward phase and by this delaying the knee extension. In SQJ and CMJ h was 0.22-0.36m and 0.33-0AOm. The work contribution from the knee was 64.5%(SE 5.9) and 76.0% (SE 9.2) and from the hip 18.8% (SE 5.8) and 133% (SE 8.7). One ballet dancer and one volleyball player performed SQJ and CMJ with a simultaneous strategy while the otller four subjects used a sequential strategy. CONCLUSION In a maximal vertical jump fram ballet and from volleyball the technical demands preset the jumping strategy. When the subjects were asked to perform SQJ and CMJ the choice of strategy seemed individual and not connected to the training background. REFERENCES (1) Hudson, J.L. (1986). Med Sci. Sports Exerc, 18,242-251 (2) Babbert, M.F. & van lngen Schenau, G.J. (1986). J Biomechanics, 21, 249•26

Vinner vi krigen? Vurdering av fremgang og resultater i militære operasjoner

Vurderingene av fremgang og resultater i NATOs militære operasjoner, benevnt operations assessment, har blitt kritisert for å være anekdotiske, og ikke gjenspeile et korrekt bilde av virkeligheten. For å øke vår kunnskap om prosessen som leder frem til disse vurderingene, og dermed bedre kunne fastslå om kritikken er berettiget, har denne studien hatt til hensikt å undersøke i hvilken grad vitenskapelige prinsipper er applisert i NATOs operations assessment-prosess. Selv om vitenskap i seg selv ikke kan garantere for sannheten, har det i studien vært lagt til grunn at kunnskap basert på vitenskap står sterkere enn andre typer kunnskap. En slik forståelse innebærer at man i utgangspunktet kan stole mer på vurderinger som helt eller delvis er basert på vitenskapelige metoder og prinsipper, enn på vurderinger som er basert på andre tilnærminger. I oppgavens første del blir NATOs beskrevne operations assessment-prosess beskrevet og analysert i lys av grunnleggende samfunnsvitenskapelige prinsipper. Undersøkelsen viser at NATOs beskrevne metode har svært mange likhetstrekk med hvordan en samfunnsvitenskapelig undersøkelse gjennomføres. Imidlertid, når det kommer til viktige metodologiske forhold som kan ha stor innvirkning på både reliabilitet og validitet, er NATOs metode ofte vagt og ufullstendig beskrevet. For å gjennomføre prosessen som beskrevet, og samtidig ivareta vitenskapelige prinsipper, synes det derfor nødvendig at en viss vitenskapelig kompetanse er tilgjengelig hos de som skal gjennomføre prosessen i virkelige operasjoner. I studiens andre del blir det undersøkt i hvilken grad NATOs beskrevne prosess faktisk blir fulgt i operasjonene. Gjennomføring av operations assessment blir undersøkt på det operasjonelle nivået i fire NATO-operasjoner siden 2010, samt ved det Forsvarets Operative Hovedkvarter (FOH) i Norge. Undersøkelsen viser at det er forskjeller mellom operasjonene, men at NATOs prosess i hovedsak følges. Studien viser at FOH er kommet kort i implementeringen av operations assessmen. For å få fortgang i implementeringen, bør det vurderes å gjennomføre operations assessment også i disse operasjonene. Av NATOs operasjoner siden 2010, peker studien mot at operasjonene i Afghanistan i minst grad gjennomfører operations assessment slik den er beskrevet av NATO. Måten assessmentprosessen gjennomføres på, er med på å svekke graden av både validitet og reliabilitet i vurderingene som gjøres, fordi viktige analyser i stor grad baseres på subjektive antakelser

A Functional Genomics Approach to Tanshinone Biosynthesis Provides Stereochemical Insights

Tanshinones are abietane-type norditerpenoid quinone natural products that are the bioactive components of the Chinese medicinal herb Salvia miltiorrhiza Bunge. The initial results from a functional genomics-based investigation of tanshinone biosynthesis, specifically the functional identification of the relevant diterpene synthases from S. miltiorrhiza, are reported. The cyclohexa-1,4-diene arrangement of the distal ring poises the resulting miltiradiene for the ensuing aromatization and hydroxylation to ferruginol suggested for tanshinone biosynthesis