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- Atterhög, Mikael, 1962-
(författare)
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The effect of competition and ownership policies on the housing market
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation consists of five studies presented in seven essays. The overall objectives are to investigate the extent and consequences of competition on the rental housing market as well as the importance of national government policies for the substitute good, i.e. owner-occupied housing. However, each essay also has specific objectives. Due to the characteristics of the housing market, one should not expect competition to be very fierce. The market characteristics are, for instance, capital-intensive, complicated and time-consuming construction processes as well as a limited supply of land in many areas. In fact, firms have a lot to gain from colluding and to avoid e.g. price wars. It is therefore theoretically more likely that housing companies will engage in “functional” or “strategic” competition such as the quality of housing services. Essay I and IV analyze the unique municipal housing market in Sweden where apartment rents are determined by negotiations between the local municipal company and the local Union of Tenants. A regression analysis is applied on data from 30 municipalities. There was a strong correlation between apartment rents at local municipal markets and the level of “external” competition (measured by the price level on the market for single-family owner occupied housing), but not with “internal” competition (measured by the market share of the municipal housing company) or the capital expenditure of the municipal housing company (presumed to reflect historical construction and renovation costs for the apartments). The dissertation also investigates the consequences on rents (essay II) and on the quality of housing services (essay III) from a local Swedish municipal housing company selling a substantial part of its apartment stock (15-40 percent) and thereby theoretically creating more competition. These essays use a quasi-experimental methodology whereby the development of the housing market in a privatization town is compared with the development in a very similar comparison town. It is found that privatization has lead to lower rents in the short- and medium-term in six out of seven privatization towns. The development of the quality of housing services was more related to the performance of each individual company and not a specific category of companies. In essay V, these results are merged and developed further. Essay VI presents a wide range of policies available for governments wishing to increase access to home ownership for low-income households and thereby increasing the pressure on rental housing companies to reduce rents. A systematic overview of policies is provided based on the four distinct time periods of a typical ‘housing career’ of a household; i.e. down payment accumulation stage, transaction stage, ownership stage and selling stage. It is found that many policies are required to meet the specific and differing needs of households for governments wishing to encourage home ownership. Essay VII describes that home ownership rates have increased in almost all industrialized countries during the period from World War II until mid-1990s. The essay analyses the implications of government policies and some other factors (e.g. national wealth, income distribution) on home ownership rates in 13 industrialized countries during the period 19702000. A fixed-effect model is applied on a panel data set. The most important result is that a statistically significant and positive correlation between government support and home ownership rates was found although this is only a preliminary conclusion since data was scarce.
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| 2. |
- Fernández-Varea, José M., et al.
(författare)
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Limitations (and merits) of PENELOPE as a track-structure code
- 2012
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 88:1-2, s. 66-70
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To outline the limitations of PENELOPE (acronym of PENetration and Energy LOss of Positrons and Electrons) as a track-structure code, and to comment on modifications that enable its fruitful use in certain microdosimetry and nanodosimetry applications.Methods: Attention is paid to the way in which inelastic collisions of electrons are modelled and to the ensuing implications for microdosimetry analysis.Results: Inelastic mean free paths and collision stopping powers calculated with PENELOPE and two well-known optical-data models are compared. An ad hoc modification of PENELOPE is summarized where ionization and excitation of liquid water by electron impact is simulated using tables of realistic differential and total cross sections.Conclusions: PENELOPE can be employed advantageously in some track-structure applications provided that the default model for inelastic interactions of electrons is replaced by suitable tables of differential and total cross sections.
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| 3. |
- Lind, Fredrik, 1978, et al.
(författare)
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12,000 Hours of Operation with Oxygen-Carriers in Industrially Relevant Scale (75,000 kWth).
- 2017
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Ingår i: VGB PowerTech.
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen carrier aided combustion (OCAC) is a novel combustion method and a spin-off from chemical-looping combustion (CLC). The core of the technique lies in the utilization of an oxygen carrier (OC) as bed material, and the purpose to enhance the distribution of oxygen in fluidized bed (FB) boilers. The concept combines the robustness of the well-established technology FB boilers with the novel features of oxygen active properties introduced by the OC. Due to several similarities, the OCAC concept can also contribute with knowledge in a transitional path for the scale-up of other chemical-looping techniques, such as CLC, from lab to industrial scale. In this work, the first experiences are presented where a 75,000 kWth CFB-boiler has been operated with ilmenite (FeTiO3) as bed material during 12,000 hours with municipal solid waste as fuel. The investigation shows that ilmenite can replace the commonly used bed material silica-sand without any retrofitting of boiler equipment, and that ilmenite enhances the mass transfer of oxygen inside the furnace. The results show that ilmenite can drastically reduce the amount of carbon monoxide in the flue gas, even when the furnace is operated with an oxygen concentration that is lower compared to ordinary silica-sand operation. Even though still being in the early stages, this concept can contribute to overcome the threshold of understanding the mass transfer and mixing conditions in industrial conditions to enable scale-up of CLC.
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