411 research outputs found
Effects of mental accounting on intertemporal choice
Two experiments with undergraduates as subjects were carried out with the aim of replicating and extending previous results showing that the implication of the behavioral life-cycle hypothesis (H. M. Shefrin & R. H. Thaler, 1988) that people classify assets in different mental accounts (current income, current assets, and future income) may explain how consumption choices are influenced by temporary income changes. In both experiments subjects made fictitious choices between paying for a good in cash or according to a more expensive installment plan after they had received an income which was either less, the same, or larger than usual. In Experiment 1 subjects were supposed to have savings so that the total assets were equal, whereas in Experiment 2 the total assets varied. The results of both experiments supported the role of mental accounts in demonstrating that subjects were unwilling to pay in cash after an income decrease even though they had access to saved money. Thus, in effect they chose to pay more for the good than they had to. Indicating a need for further refinement of the concept of mental account, choices to pay in cash after an income decrease tended to be more frequent when the consumption and savings motives were compatible than when they were incompatible. Furthermore, increasing the total assets made subjects more willing to pay in cash after an income decrease
HIV and hepatitis C prevention among people who inject drugs in Sweden : harm reduction policies, risk behaviour interventions and outcomes
People who inject drugs (PWID) is a heterogeneous and hard-to-reach group due to legal
implications, stigma and discrimination. PWID are vulnerable to various poor health
outcomes including HIV and hepatitis due to ongoing injection and sexual risk behaviours,
various forms of abuse, poor health seeking behaviours, and limited access to- and retention
in prevention and care programs. General knowledge about PWID, hepatitis C (HCV) and
HIV-risks is good, but less is known about certain sub-populations such as women who inject
drugs (WWID). In order to reach PWID with harm reduction, primarily to reduce their risk of
HCV and HIV, countries have introduced needle exchange programs (NEP). However, low
NEP-availability and insufficient awareness of gender-specific and other sub-group barriers
and needs challenges the coverage, uptake and effectiveness of harm reduction for PWID.
The overall aim of this thesis was to analyse NEP-development in Sweden and to study
determinants for injection and sexual risk behaviours among PWID over time in Stockholm,
Sweden. In paper I, NEP-development in Sweden was analysed over time (1985–2017) in
relation to Swedish drug and health policy. We found that NEP-development was obstructed
for a long period because of costly time- and resource-intensive obstacles and processes, e.g.
a municipal veto towards starting NEP, involving actor-coalitions, absence of evidence and
ideological and individual moral dimensions on both policy and implementation levels. With
renewed focus on the individual drug user-perspective, accumulation of evidence, a NEP-law,
changes in actor-coalitions and removal of the veto, Sweden saw a fast NEP-development.
In paper II, determinants for risk behaviours among PWID (n=2,150) at enrolment in remand
prisons were studied over time from 2002–2012. Female sex, homelessness, young age and
amphetamine injection drug use (IDU) were determinants associated with high levels of
injection risk behaviours. Further, injection risk behaviours decreased over time among new
enrolled PWID in remand prisons.
In paper III, determinants and injection risk behaviours at
enrolment and over time (2013–2018) were studied among PWID (n=2,860) in the first NEP
in Stockholm. An overall significant reduction in injection risk behaviours was found over
time and in relation to most enrolment determinants. Female sex, homelessness and
amphetamine use were determinants that correlated to an increased risk of sharing
needle/syringes and paraphernalia at enrolment, whereas opioid substitution therapy (OST)
appeared protective.
In paper IV, subgroup determinants for injection and sexual risk
behaviours and program retention were studied among WWID (n=697) in the Stockholm
NEP (2013–2018). Homelessness, amphetamine-IDU, not being in OST and a history of
being sectioned (i.e. psychiatric or addiction-related compulsory care) was associated with
high injection risk behaviours. Younger age, stable civil status, not in OST and being HIVnegative
were associated with higher sexual risk behaviour. WWID were more likely than
men to remain in the NEP over time, and previously sectioned WWID were associated with
risk for being LTFU.
To conclude, our findings highlight the need to better understand the
needs of various sub-groups of PWID to successfully tailor harm reduction interventions and
scale-up NEP-programs to prevent the spread and eliminate HCV and HIV by 2030, as
proposed by the WHO and UNAIDS
Hadronic Production of Gamma Rays and Starburst Galaxies
The Milky Way has been estabished to emit gamma rays. These gamma rays are
presumably dominated by decays of neutral pions, although inverse Compton
scatterings and bremsstrahlung also contribute. It is plausible that other
galaxies can be diffuse sources of gamma rays in a similar manner. Starburst
galaxies are particularly interesting to study as they are expected to have
much higher cosmic-ray fluxes and interstellar matter densities. The neutral
pions are created in cosmic-ray interactions with interstellar matter.
Presented here is an overview of the recent work by Karlsson and co-workers on
proton-proton interactions and the resulting secondary particle inclusive cross
sections and angular distributions. This model can be used to calculated the
component of the gamma-ray yield and spectrum from a starburst
galaxy. The yield is expected to increase significantly (30% to 50%) and the
spectrum to be harder than the incident proton spectrum.Comment: 4 pages, 4 figures, submitted for the Proceedings of the 4th
Heidelberg International Symposium on High Energy Gamma-Ray Astronomy, July
7-11, 2008, in Heidelberg, German
The Path Dependency of former monopolists A case study of Scandinavian Airlines System
Abstract Title: The Path Dependency of former monopolists Seminar date: 2013-05-30 Course: FEKN90 Företagsekonomi: Examensarbete på Civilekonomprogrammet (30 ECTS) Authors: Niklas Sandberg and Henrik Karlsson Advisor: Matts Kärreman Five key words: Monopolist, Path dependency, Strategy, Competition and Deregulation Purpose: To explain how path dependency is affecting the strategies of former monopolists after that their markets are deregulated. Methodology: For this thesis research we have mainly applied an inductive approach based on a qualitative research method including unstructured interviews. Theoretical Framework: To analyze path dependency from a strategic and industrial perspective Porter’s Diamond, the Path dependency theory, SWOT-analysis and Porter’s Generic Strategies have been selected. These models and theories have been chosen because of their explanatory advantages and inbound relations. Empirical material: The Empirical data primarily comes from five interviews and 20 annual reports. These sources have been presented together in order to provide a covering background for the analysis. Conclusions: This thesis suggests that former monopolists continue to be affected by path dependency after that their markets are deregulated. The structures and strategies of monopolists operating in a regulated market are built on the belief that they are not facing competition. Therefore overall efficiency particularly in terms of cost structure is not emphasized during regulation. Once the market is deregulated new entrants enter with cost structures based on markets with free competition. The new entrants, not being strategically path dependent, may also implement new business models. The former monopolist is challenged by limited strategic space because of its path dependent structure. This limited strategic space caused by path dependency negatively affects its relative competitiveness
Self-control and loss aversion in intertemporal choice
The life-cycle theory of saving behavior (Modigliani, 1988) suggests that humans strive towards an equal intertemporal distribution of wealth. However, behavioral life-cycle theory (Shefrin & Thaler, 1988) proposes that people use self-control heuristics to postpone wealth until later in life. According to this theory, people use a system of cognitive budgeting known as mental accounting. In the present study it was found that mental accounts were used differently depending on if the income change was positive or negative. This was shown both in a representative nationwide sample of households and in a student sample. Respondents were more willing to cut down on their propensity to consume when faced with an income decrease than to raise it when the income increased. Furthermore, contrary to the predictions of behavioral life-cycle theory, it was found that the respondents adjusted their propensity to consume the most when the income increases or decreases took place immediately. Hence, it is suggested that theories of intertemporal choice (e.g., Loewenstein, 1988; Loewenstein & Prelec, 1992) provide a better account of the data than does the behavioral lifecycle theory
Explanations of effects of prior income changes on bying decisions
Two experiments with undergraduates as subjects tested explanations of how a prior temporary income change influences choices between buying and deferred buying. In Experiment 1 predictions from the behavioral life-cycle theory (Shefrin & Thaler, 1988), the renewable resources model (Linville & Fischer, 1991) and the loss-sensitivity principle (Garling & Romanus, 1997) were contrasted. The results are inconsistent with the latter two explanations since the framing of buying as positive (buying a new model of a product) or negative (replacing a broken product) did not interact with the income change. Congruent with the behavioral life-cycle theory, willingness to buy was greater when subjects received a temporary income increase than when they received a temporary income decrease although total assets were equal. Further support for the behavioral life-cycle theory is obtained in Experiment 2 where four income-change conditions and durable and nondurable goods are compared
Indicating and managing BEV range issues in two-car households
We discuss from various perspectives the range limitation; possible indicators, different relaxation options and the actual adaptation in two-car households, using GPS-loggings of both cars simultaneously for 1-3 months in 64 two-car households, and interviews after a BEV trial in 25 of these households. Indicators such as DRA are less useful in two-car households. Instead the flexibility in such households may drastically reduce the range issues. The actual adaptation in households shows that there are numerous reasons to why the options are not fully utilized. Still, none of the test households stated a perceived limitation due to range
How do users adapt to a short-range battery electric vehicle in a two-car household? Results from a trial in Sweden
We supplied 25 two-car households with a short-range battery electric vehicle (BEV) to study their adaptation to a BEV replacing one of their conventional cars. The data includes GPS-measured driving of the households’ two original cars for 2–3 months, and for the BEV and the remaining conventional car for 3–4 months. We performed interviews with the households before and after the BEV trial period. We can thus compare the change in measured driving patterns and the users’ experienced adaptation in relation to their measured driving adaptation. We find large heterogeneity in measured adaptation, with some users driving the BEV more than the replaced car and some less. Most users state a preference for using the BEV, but this is not always detectable in the GPS data. Similarly, expected issues with the range limitation from the GPS data do not predict satisfaction with the BEV from the qualitative data
Effects of mental accounting on intertemporal choices
Two experiments with undergraduates as subjects were carried out with the aim of replicating and extending previous results showing that the implication of the behavioral life-cycle hypothesis (H. M. Shefrin & R. H. Thaler, 1988) that people classify assets in different mental accounts (current income, current assets, and future income) may explain how consumption choices are influenced by temporary income changes. In both experiments subjects made fictitious choices between paying for a good in cash or according to a more expensive installment plan after they had received an income which was either less, the same, or larger than usual. In Experiment 1 subjects were supposed to have savings so that the total assets were equal, whereas in Experiment 2 the total assets varied. The results of both experiments supported the role of mental accounts in demonstrating that subjects were unwilling to pay in cash after an income decrease even though they had access to saved money. Thus, in effect they chose to pay more for the good than they had to. Indicating a need for further refinement of the concept of mental account, choices to pay in cash after an income decrease tended to be more frequent when the consumption and savings motives were compatible than when they were incompatible. Furthermore, increasing the total assets made subjects more willing to pay in cash after an income decrease
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