| 1. |
- Almerud, Jakob, 1984-
(författare)
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Public Policy, Household Finance and the Macroeconomy
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis contains four separate essays, spanning questions of the interaction between public policy, household finance and the macroeconomy. How does public policy affect macroeconomic outcomes, and the choices and welfare of households, and what are households’ optimal financial responses to changes in macroeconomic environments? Furthermore, the thesis includes a development of a method, which is helpful to answer questions like the ones stated above. The first essay, Optimal Public Policy in a Multi-Sector Economy with Asymmetric Shocks, shows how fiscal policy can complement monetary policy. It is shown that fiscal policy can be used to improve macroeconomic outcomes and make the economy more efficient. Since fiscal policy, in general, includes more instruments than monetary policy, it is possible to neutralize several frictions in the economy simultaneously. This is shown in a general equilibrium model with dynastic households, where firms face monopolistic competition, sticky prices, productivity shocks and cost-push shocks. The second essay, On the Design of Mortgage Default Legislation, asks how different types of mortgage contracts interact with different types of mortgage default policies regarding the probability of a default on home-owner’s mortgage. The different types of mortgage contracts analyzed are fixed rate annuity mortgages, adjustable rate amortized mortgages and adjustable rate non-amortized mortgages. The mortgage default policies span from non-recourse (where the mortgage lender takes all the default risk) to full recourse (where the borrower takes all the default risk). It is shown that a “borrower friendly” non-recourse policy is, as the one implemented in many parts of the United States, not necessarily borrower friendly due to its effect on the risk premium. This is investigated in a model with finitely lived households and an endogenous risk premium. The third essay, On The Empirical Relevance of Cointegration Between Stock Market Returns and Labor Income on Optimal Portfolio Choice, investigates how finitely lived households optimally choose a portfolio consisting of risk-free bonds and risky equity, and how this choice is affected by the long-run correlation between risky (cumulative) equity returns and stochastic labor income. More specifically, I investigate if the empirical cointegration (long-run correlation) between the two variables is strong enough to affect the optimal portfolio choice. It is shown that it is not. Cointegration exists between the two variables, but the speed-of-adjustment back to the cointegration equilibrium is to slow to have a significant effect on the households’ optimal portfolios. The fourth essay, Solving Dynamic Programming Problems Using Stochastic Grids and Nearest-Neighbor Interpolation, describes a new computational method, which is used in the second and third essays. The method is developed to solve models with finitely lived households who face a complex economic environment. Post-state decision rules for the households are used together with simulated stochastic grids over the exogenous variables. By simulating the grids it is possible to reduce the number of grid points that the model is solved for, thereby making it significantly faster to solve models with many exogenous state variables. It is shown that it is possible to solve non-linear life-cycle models including at least eight state variables relatively quickly on a standard desktop computer.
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| 2. |
- Dorn, Reinhold J., et al.
(författare)
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CRIRES+ on sky : High spectral resolution at infrared wavelength enabling better science at the ESO VLT
- 2022
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Ingår i: Ground-Based And Airborne Instrumentation For Astronomy IX. - : SPIE - International Society for Optical Engineering. - 9781510653504 - 9781510653498
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Konferensbidrag (refereegranskat)abstract
- CRIRES+ extended the capabilities of CRIRES, the CRyogenic InfraRed Echelle Spectrograph. It transformed this VLT instrument into a cross-dispersed spectrograph to increase the wavelength range that is covered simultaneously by a factor of ten. In addition, a new detector focal plane array of three Hawaii 2RG detectors with a 5.3 mu m cut-off wavelength replaced the existing detectors. Amongst many other improvements a new spectropolarimetric unit was added and the calibration system has been enhanced. The instrument was installed at the VLT on Unit Telescope 3 beginning of 2020 and successfully commissioned and verified for science operations during 2021, partly remote from Europe due to the pandemic. The instrument was subsequently offered to the community from October 2021 onwards. This article describes the performance and capabilities of this development and presents on sky results.
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| 3. |
- Klein, Daniel B., Adjungerad professor
(författare)
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What 21st-Century Works Will Merit a Close Reading in 2050? : Second Tranche of Responses
- 2021
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Ingår i: Econ Journal Watch. - : Econ Journal Watch. - 1933-527X. ; 18:1, s. 164-191
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Adam Smith applied the expression “never to be forgotten” to two thinkers he knew personally, born more than 300 years ago, and those two thinkers are not yet forgotten.We undertook the present query in 2020, looking a mere 30 years ahead. What 21st-century works will merit a close reading in 2050? That is the question asked of Econ Journal Watch authors (specifically: those who authored material in sections other than the Comments section of the journal). The previous issue of this journal provided responses from authors with last names beginning A through K (link). Here we present nineteen responses from authors L through Z.
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| 4. |
- Skult, Eva, 1945-
(författare)
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Studies in Saving under Uncertainty
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of three essays.In Precautionary Saving under Correlated Risk, I show that the sign of the correlation between the random variables might determine whether saving increases or decreases when risk is introduced. Precautionary saving is thus not confirmed. In the second part of this chapter, the consumer must also allocate her saving between an insurance and an interest-bearing asset. It is shown that switching the sign of correlation changes the optimal insurance ratio and probably also optimal saving.Saving and Portfolio Choice by Mutually Altruistic Consumers treats the effects of mutual altruism between two individuals. Compared to the Utilitarian social optimum there is, on the one hand, a tendency to higher saving and lower risk share resulting from the higher uncertainty of future income in the Nash equilibrium. On the other hand, there is a tendency to lower saving and higher risk share arising from the possibility of a free ride on the generosity of others, named "Samaritan's Dilemma". Analytically, it was not possible to determine the size or the direction of divergences in the choice variables. Numerical examples show that the effect of the Samaritan's Dilemma outweighs the effect of the greater uncertainty of future income in the Nash equilibrium. However, the divergence in saving between the two solutions is rather small.In the literature, uncertain lifetime has been used to explain both unexpectedly low and unexpectedly high saving by the elderly. In The Effect of Uncertain Lifetime on the Saving of the Elderly, risk is introduced into the remaining lifetime and the consequences of a background risk are investigated. Introducing uncertain lifetime into the certainty model results in a slower decumulation of wealth from the date of retirement. On the contrary, introducing uncertain lifetime into a model with uncertain investment income results in a swifter decumulation and an earlier depletion of wealth.
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| 5. |
- Brucalassi, Anna, et al.
(författare)
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Full System Test and early Preliminary Acceptance Europe results for CRIRES
- 2018
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Ingår i: Ground-Based And Airborne Instrumentation For Astronomy VII. - : SPIE. - 9781510619586
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Konferensbidrag (refereegranskat)abstract
- CRIRES+ is the new high-resolution NIR echelle spectrograph intended to be operated at the platform B of VLT Unit telescope UT3. It will cover from Y to M bands (0.95-5.3um) with a spectral resolution of R = 50000 or R = 100000. The main scientific goals are the search of super-Earths in the habitable zone of low-mass stars, the characterisation of transiting planets atmosphere and the study of the origin and evolution of stellar magnetic fields. Based on the heritage of the old adaptive optics (AO) assisted VLT instrument CRIRES, the new spectrograph will present improved optical layout, a new detector system and a new calibration unit providing optimal performances in terms of simultaneous wavelength coverage and radial velocity accuracy (a few m/s). The total observing efficiency will be enhanced by a factor of 10 with respect to CRIRES. An innovative spectro-polarimetry mode will be also offered and a new metrology system will ensure very high system stability and repeatability. Fiinally, the CRIRES+ project will also provide the community with a new data reduction software (DRS) package. CRIRES+ is currently at the initial phase of its Preliminary Acceptance in Europe (PAE) and it will be commissioned early in 2019 at VLT. This work outlines the main results obtained during the initial phase of the full system test at ESO HQ Garching.
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| 6. |
- Klein, Paul
(författare)
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Papers on the macroeconomics of fiscal policy
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of six independent papers, which are summarized as follows."Stochastic Fiscal Policy and the Swedish Business Cycle" shows that fluctuations in distortive taxes can account for some of the key features of the Swedish post-war business cycle. The empirical fit of a simple stochastic growth model is found to significantly improve when it is amended to include imperfectly predictable fluctuations in payroll taxes, consumption taxes and government consumption."Swedish Income Taxes 1951-1990" reconstructs Swedish income tax schedules for the years 1951-1990. The main finding is that tax schedules can be very well approximated by an isoelastic function."The Relationship Between Money and Interest Rates: How Well Do Equilibrium Models Perform?" studies the extent to which dynamic monetary equilibrium models can account for the differences in the character of the money demand curve between Sweden and the United States. The main finding is that they can account for the main properties of the data remarkably well."The Welfare Costs of Stochastic Distortionary Taxation" presents estimates of the welfare costs of distortionary taxation (including inflation) calculated by using general equilbirium models calibrated for the United States and Sweden. The main finding is that the total welfare costs of the distortionary taxes are about five times higher in Sweden than in the United States."The Welfare Gains From Optimal Tax Reform" attempts to calculate how much the representative household in the United States would gain by a transition from current fiscal and monetary policy to a Ramsey optimal tax and inflation policy, which finances given government purchases and transfer payments in the most efficient way possible. I find that those gains correspond to an increment in consumption of about 3.8 percent."Using the Generalized Schur Form to Solve a System of Linear Expectational Difference Equations" presents a quick and convenient way of solving systems of linear expectational difference equations. It also presents very weak sufficient conditions for the existence of a unique solution.
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| 7. |
- Piskunov, Nikolai, professor, 1957-, et al.
(författare)
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A unique infrared spectropolarimetric unit for CRIRES
- 2018
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Ingår i: GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY VII. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510619586
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Konferensbidrag (refereegranskat)abstract
- High-resolution infrared spectropolarimetry has many science applications in astrophysics. One of them is measuring weak magnetic fields using the Zeeman effect. Infrared domain is particularly advantageous as Zeeman splitting of spectral lines is proportional to the square of the wavelength while the intrinsic width of the line cores increases only linearly. Important science cases include detection and monitoring of global magnetic fields on solar-type stars, study of the magnetic field evolution from stellar formation to the final stages of the stellar life with massive stellar winds, and the dynamo mechanism operation across the boundary between fully-and partially-convective stars. CRIRES+ (the CRIRES upgrade project) includes a novel spectropolarimetric unit (SPU) based on polarization gratings. The novel design allows to perform beam-splitting very early in the optical path, directly after the tertiary mirror of the telescope (the ESO Very Large Telescope, VLT), minimizing instrumental polarization. The new SPU performs polarization beam-splitting in the near-infrared while keeping the telescope beam mostly unchanged in the optical domain, making it compatible with the adaptive optics system of the CRIRES+ instrument. The SPU consists of four beam-splitters optimized for measuring circular and linear polarization of spectral lines in YJ and HK bands. The SPU can perform beam switching allowing to correct for throughput in each beam and for variations in detector pixel sensitivity. Other new features of CRIRES+, such as substantially increased wavelength coverage, stability and advanced data reduction pipeline will further enhance the sensitivity of the polarimetric mode. The combination of the SPU, CRIRES+ and the VLT is a unique facility for making major progress in understanding stellar activity. In this article we present the design of the SPU, laboratory measurements of individual components and of the whole unit as well as the performance prediction for the operation at the VLT.
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