This study develops a dynamic pricing model with a quality substitutable product, taking into account strategic and myopic consumers. In each of the two periods, the firm can choose between offering a high quality product, a low quality product or both and the corresponding price for the product. Strategic consumers compare current utility with future utility in order to decide the time of purchase and the quality of the product in an attempt to maximize their utilities. Myopic consumers consider only current utility in purchasing of the products. We generate scenarios, prove whether a scenario is feasible and which scenario produces the best profit for the firm. Our result suggests that the firm obtains the best profit when it provides only high quality products in each of the two periods. In other words, the firm does not have to offer quality substitution as intertemporal substitution suffices to maximize the expected profit.

Due to health problems and the negative externalities associated with cigarette consumption, many governments try to discourage cigarette consumption by increasing its price through taxation. However, cigarette, like the other addictive goods, is viewed as that it is not sensitive to demand rules and the market forces. This study analyses the effect of price increase on cigarette consumption. We used Swedish time series data from 1970 to 2010. Our results reveal that though cigarette is addictive substance its demand is sensitive to changes in the price. Estimates from this study indicate short-run price-elasticity of -0.29 and the long run price elasticity of -0.47.

This study develops a dynamic pricing model with a quality substitutable product, taking into account strategic and myopic consumers. In each of the two periods, the firm can choose between offering a high quality product, a low quality product or both and the corresponding price for the product. Strategic consumers compare current utility with future utility in order to decide the time of purchase and the quality of the product in an attempt to maximize their utilities. Myopic consumers consider only current utility in purchasing of the products. We generate scenarios, prove whether a scenario is feasible and which scenario produces the best profit for the firm. Our result suggests that the firm obtains the best profit when it provides only high quality products in each of the two periods. In other words, the firm does not have to offer quality substitution as intertemporal substitution suffices to maximize the expected profit.

We test the performance of myopic and farsighted stability concepts in a network formation experiment with a stream of payoffs and relatively unstructured link formation process. A subtle treatment variation demonstrates clearly the power of myopic stability concepts in precisely identifying the set of the most stable networks. However, we also find support for the predictions of farsighted concepts of stability, especially those that assume players' pessimism about the eventual outcome of a deviation. This is the first study to demonstrate that there exist environments where farsighted stability concepts identify empirically stable networks that are not identified by myopic concepts. Thus, myopic stability concepts are not necessarily sufficient to predict all stable outcomes in empirical applications.

In previous research, aggregation of returns has been found as a way to counteract the risk averse behavior that is the result of investors' myopia. This paper expands the study of aggregation by analyzing its effect on forward looking probabilities. Namely, through the disaggregation of future information, subjects become myopic and trade with varying risk preferences. In an experimental market, subjects trading securities with disaggregated forward looking information are found to 'buy high and sell low', while subjects trading the same securities, but with aggregated information, trade with more consistent risk preferences.

We examine in an experiment the causes, consequences and possible cures of myopic loss aversion (MLA) for investment behaviour under risk. We find that both, investment horizons and feedback frequency contribute almost equally to the effects of MLA. Longer investment horizons and less frequent feedback lead to higher investments. However, when given the choice, subjects prefer on average shorter investment horizons and more frequent feedback. Exploiting the status quo bias by setting a long investment horizon or low feedback frequency as a default turns out to be a successful behavioural intervention that increases investment levels. (author´s abstract) / Series: Department of Economics Working Paper Series

La mégaline est un récepteur endocytique multiligand essentiellement connu comme récepteur clé pour la réabsorption protéique rénale. Au cours du développement embryonnaire murin la mégaline a été impliquée dans le développement du prosencéphale et de l’œil mais la mortalité périnatale des souris Meg-/- empêche sone étude à des stades ultérieurs. Pour analyser le rôle de la mégaline dans le système visuel nous avons généré dans le laboratoire des souris conditionnelles FoxG1-Cre MegL/L.L’analyse phénotypique des souris mutantes montre que l’absence de la mégaline dans le neuroépithélium antérieur conduit à une augmentation anormale et progressive de la taille de l’œil accompagnée par un amincissement de la rétine et la diminution, entre autres, des cellules ganglionnaires. Ces observations immunomorphologiques suggèrent que les souris mutantes présentent des signes de myopie forte et sont confirmées par l’analyse ophtalmologique. Les analyses biochimiques des souris mutantes montrent que l’absence de mégaline entraine des modification dans la structure et la fonction du corps ciliaire, à l’origine de cet élongation excessive du globe oculaire. Les résultats obtenus montent que les souris Foxg1-Cre MegL/L sont le premier modèle génétique murin qui reproduit les caractéristiques de la myopie forte. L’élucidation des mécanismes physiopathologiques sous-jacents au développement de la myopie est un préalable indispensable à l’élaboration d’en éventuel traitement préventif, espoir pour les 0,5% à 2% de la population touchés par la cécité liée aux complications de la myopie forte. / Megalin is a large multiligand endocytic receptor essentially known as the key receptor for protein reabsorption in the renal proximal tubule. Murin megalin appears to be essential for early forebrain and eye development but the perinatal lethality of Meg-/- mice precludes further analysis. To study the implication of megalin in the formation of the eye we generated (in the laboratory ) FoxG1-Cre MegL/L mice lacking megalin specifically in the anterior neuroepithelium.The phenotypic analysis of these mice show that they suffer from an excessive and progressive eye growth associated with retinal thinning and a strong decrease of some retinal cell types including the ganglion cells. The immunomorphological studies suggest that the mutant mice are highly myopic which is confirmed by the ophtalmological analysis data. The biochemical analysis of these mutant mice shows that the absence of megalin causes structural and functional modifications in the ciliary epithelium, leading to the excessive elongation of the eyeball. These results show that the FoxG1-Cre MegL/L mice are the first murine genetic model recapitulating the characteristics of high myopia. The elucidation of underlying physiopathological mechanisms of high myopia development is essential for the elaboration of a preventive treatment, hope for 0,5 to 2% of the population suffering from blindness caused by the complications of high myopia.

The main experimental work of this thesis has been a cross-sectional study of the prevalence of refractive error and its biometric correlates in Middle Eastern adults. In addition dynamic accommodative responses and twenty-four hour axial length fluctuations were investigated in young myopic adults. The prevalence of myopia in 3000 Middle Eastern adults (age range 17-40 years) was similar to previously reported levels of myopia in the West. Myopia was associated with a higher level of education, occupations with a high nearwork demand and positive family history of myopia; all of which have been identified as risk factors for myopia development and progression Diurnal variations in axial length (AL) of similar magnitude to those previously reported in emmetropes were observed in myopes recruited in the current thesis. However, the pattern of the diurnal variation in AL was significantly different between early-onset myopes (EOMs) and late-onset myopes (LOMs). There were no significant differences between EOMs and LOMs in the dynamic accommodative response to a sinusoidally oscillating target. The accommodative phase lag was increased following 30 minute adaptation to myopic defocus using +2.00 D lens. However, intense prolonged (30 minute) nearwork was found to have no effect on accommodative gain or phase lag. A number of recommendations for further work on the prevalence of refractive error in the Middle East are suggested along with further research on diurnal AL variations and dynamic accommodative responses in EOMs and LOMs.

No / The aims of the research may be outlined as follows: to measure the degree of transient axial elongation during the accommodation response in emmetropic and myopic young adults. To evaluate the effect of refractive error and accommodative demand on transient axial elongation of the eye. Axial length of the right eye was measured in 30 emmetropes and 30 myopes, by using the IOLMaster (Carl Zeiss Meditec, Inc., Dublin, CA), while accommodative stimuli of 0, 2, 4 and 6 D were presented with a Badal optometer. Axial length increased in both emmetropic and myopic subjects during short periods of accommodative stimulation. Greater transient increases in axial length were observed in myopic than in emmetropic subjects. The mean axial elongation with a 6-D stimulus to accommodation was 0.037 mm in emmetropes and 0.058 mm in myopes (P = 0.02). The degree of transient axial elongation correlated well with the stimulus to accommodation in emmetropes and myopes. Anterior chamber depth decreased, on average, by 0.19 mm in emmetropes and 0.18 mm in myopes when observing a 6-D stimulus to accommodation. During relatively short periods of accommodative stimulation, axial length increases in both emmetropic and myopic young adults. At higher levels of accommodative stimulation, a significantly greater transient increase in axial length is observed in myopic subjects than in their emmetropic counterparts.

The main experimental work of this thesis has been a cross-sectional study of the prevalence of refractive error and its biometric correlates in Middle Eastern adults. In addition dynamic accommodative responses and twenty-four hour axial length fluctuations were investigated in young myopic adults. The prevalence of myopia in 3000 Middle Eastern adults (age range 17-40 years) was similar to previously reported levels of myopia in the West. Myopia was associated with a higher level of education, occupations with a high nearwork demand and positive family history of myopia; all of which have been identified as risk factors for myopia development and progression Diurnal variations in axial length (AL) of similar magnitude to those previously reported in emmetropes were observed in myopes recruited in the current thesis. However, the pattern of the diurnal variation in AL was significantly different between early-onset myopes (EOMs) and late-onset myopes (LOMs). There were no significant differences between EOMs and LOMs in the dynamic accommodative response to a sinusoidally oscillating target. The accommodative phase lag was increased following 30 minute adaptation to myopic defocus using +2.00 D lens. However, intense prolonged (30 minute) nearwork was found to have no effect on accommodative gain or phase lag. A number of recommendations for further work on the prevalence of refractive error in the Middle East are suggested along with further research on diurnal AL variations and dynamic accommodative responses in EOMs and LOMs.