996 resultados para Shopping-time
Resumo:
Our work is based on a simpliÖed heterogenous-agent shoppingtime economy in which economic agents present distinct productivities in the production of the consumption good, and di§erentiated access to transacting assets. The purpose of the model is to investigate whether, by focusing the analysis solely on endogenously determined shopping times, one can generate a positive correlation between ináation and income inequality. Our main result is to show that, provided the productivity of the interest-bearing asset in the transacting technology is high enough, it is true true that a positive link between ináation and income inequality is generated. Our next step is to show, through analysis of the steady-state equations, that our approach can be interpreted as a mirror image of the usual ináation-tax argument for income concentration. An example is o§ered to illustrate the mechanism.
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Several works in the shopping-time and in the human-capital literature, due to the nonconcavity of the underlying Hamiltonian, use Örst-order conditions in dynamic optimization to characterize necessity, but not su¢ ciency, in intertemporal problems. In this work I choose one paper in each one of these two areas and show that optimality can be characterized by means of a simple aplication of Arrowís (1968) su¢ ciency theorem.
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This paper investigates which properties money-demand functions have to satisfy to be consistent with multidimensional extensions of Lucasí(2000) versions of the Sidrauski (1967) and the shopping-time models. We also investigate how such classes of models relate to each other regarding the rationalization of money demands. We conclude that money demand functions rationalizable by the shoppingtime model are always rationalizable by the Sidrauski model, but that the converse is not true. The log-log money demand with an interest-rate elasticity greater than or equal to one and the semi-log money demand are counterexamples.
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Recent data have shown that the percentage of time spent preparing food has decreased during the past few years, and little information is know about how much time people spend grocery shopping. Food that is pre-prepared is often higher in calories and fat compared to foods prepared at home from scratch. It has been suggested that, because of the higher energy and total fat levels, increased consumption of pre-prepared foods compared to home-cooked meals can lead to weight gain, which in turn can lead to obesity. Nevertheless, to date no study has examined this relationship. The purpose of this study is to determine (i) the association between adult body mass index (BMI) and the time spent preparing meals, and (ii) the association between adult BMI and time spent shopping for food. Data on food habits and body size were collected with a self-report survey of ethnically diverse adults between the ages of 17 and 70 at a large university. The survey was used to recruit people to participate in nutrition or appetite studies. Among other data, the survey collected demographic data (gender, race/ethnicity), minutes per week spent in preparing meals and minutes per week spent grocery shopping. Height and weight were self-reported and used to calculate BMI. The study population consisted of 689 subjects, of which 276 were male and 413 were female. The mean age was 23.5 years, with a median age of 21 years. The fraction of subjects with BMI less than 24.9 was 65%, between 25 and 29.9 was 26%, and 30 or greater was 9%. Analysis of variation was used to examine associations between food preparation time and BMI. ^ The results of the study showed that there were no significant statistical association between adult healthy weight, overweight and obesity with either food preparation time and grocery shopping time. Of those in the sample who reported preparing food, the mean food preparation time per week for the healthy weight, overweight, and obese groups were 12.8 minutes, 12.3 minutes, and 11.6 minutes respectively. Similarly, the mean weekly grocery shopping for healthy, overweight, and obese groups were 60.3 minutes per week (8.6min./day), 61.4 minutes (8.8min./day), and 57.3 minutes (8.2min./day), respectively. Since this study was conducted through a University campus, it is assumed that most of the sample was students, and a percentage might have been utilizing meal plans on campus, and thus, would have reported little meal preparation or grocery shopping time. Further research should examine the relationships between meal preparation time and time spent shopping for food in a sample that is more representative of the general public. In addition, most people spent very little time preparing food, and thus, health promotion programs for this population need to focus on strategies for preparing quick meals or eating in restaurants/cafeterias. ^
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Bellman's methods for dynamic optimization constitute the present mainstream in economics. However, some results associated with optimal controI can be particularly usefuI in certain problems. The purpose of this note is presenting such an example. The value function derived in Lucas' (2000) shopping-time economy in Infiation and Welfare need not be concave, leading this author to develop numerical analyses to determine if consumer utility is in fact maximized along the balanced path constructed from the first order conditions. We use Arrow's generalization of Mangasarian's results in optimal control theory and develop sufficient conditions for the problem. The analytical conclusions and the previous numerical results are compatible .
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This work adds to Lucas (2000) by providing analytical solutions to two problems that are solved only numerically by the author. The first part uses a theorem in control theory (Arrow' s sufficiency theorem) to provide sufficiency conditions to characterize the optimum in a shopping-time problem where the value function need not be concave. In the original paper the optimality of the first-order condition is characterized only by means of a numerical analysis. The second part of the paper provides a closed-form solution to the general-equilibrium expression of the welfare costs of inflation when the money demand is double logarithmic. This closed-form solution allows for the precise calculation of the difference between the general-equilibrium and Bailey's partial-equilibrium estimates of the welfare losses due to inflation. Again, in Lucas's original paper, the solution to the general-equilibrium-case underlying nonlinear differential equation is done only numerically, and the posterior assertion that the general-equilibrium welfare figures cannot be distinguished from those derived using Bailey's formula rely only on numerical simulations as well.
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This note provides necessary and su¢cient conditions for some speci…c multidimensional consumer’s surplus welfare measures to be well posed (path independent). We motivate the problem by investigating partial-equilibrium measures of the welfare costs of in‡ation. The results can also be used for checking path independence of alternative de…nitions of Divisia indexes of monetary services. Consumer theory classically approaches the integrability problem by considering compensated demands, homothetic preferences or quasi-linear utility functions. Here, instead, we consider demands of monetary assets generated from a shopping-time perspective. Paralleling the above mentioned procedure, of …nding special classes of utility functions that satisfy the integrability conditions, we try to infer what particular properties of the transacting technology could assure path independence of multidimensional welfare measures. We show that the integrability conditions are satis…ed if and only if the transacting technology is blockwise weakly separable. We use two examples to clarify the point.
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This paper presents three contributions to the literature on the welfare cost of ináation. First, it introduces a new sensible way of measuring this cost - that of a compensating variation in consumption or income, instead of the equivalent variation notion that has been extensively used in empirical and theoretical research during the past fiftt years. We Önd this new measure to be interestingly related to the proxy measure of the shopping-time welfare cost of ináation introduced by Simonsen and Cysne (2001). Secondly, it discusses for which money-demand functions this and the shopping-time measure can be evaluated in an economically meaningful way. And, last but not least, it completely orders a comprehensive set of measures of the welfare cost of ináation for these money-demand specification. All of our results are extended to an economy in which there are many types of monies present, and are illustrated with the log-log money-demand specification.
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Esta tese é uma coleção de quatro artigos em economia monetária escritos sob a supervisão do Professor Rubens Penha Cysne. O primeiro desses artigos calcula o viés presente em medidas do custo de bem-estar da inflação devido a não se levar em conta o potencial substitutivo de moedas que rendem juros, como depósitos bancários.[1] O segundo se concentra na questão teórica de se comparar os escopos dos tradicionais modelos money-in-the-utility-function e shopping-time através do estudo das propriedades das curvas de demanda que eles geram.[2] O terceiro desses trabalhos revisita um artigo clássico de Stanley Fischer sobre a correlação entre a taxa de crescimento da oferta monetária e a taxa de acumulação de capital no caminho de transição.[3] Finalmente, o quarto diz respeito à posição relativa de cada uma de seis medidas do custo de bem-estar da inflação (uma das quais é nova) em relação às outras cinco, e uma estimativa do erro relativo máximo em que o pesquisador pode incorrer devido a sua escolha de empregar uma dessas medidas qualquer vis-à-vis as outras.[4] This thesis collects four papers on monetary economics written under the supervision of Professor Rubens Penha Cysne. The first of these papers assesses the bias occuring in welfare-cost-of-inflation measures due to failing to take into consideration the substitution potential of interest-bearing monies such as bank deposits.[1] The second one tackles the theoretical issue of comparing the generality of the money-in-the-utility-function- and the shopping-time models by studying the properties of the demand curves they generate.[2] The third of these works revisits a classic paper by Stanley Fischer on the correlation between the growth rate of money supply and the rate of capital accumulation on the transition path.[3] Finally, the fourth one concerns the relative standing of each one of six measures of the welfare cost of inflation (one of which is new) with respect to the other five, and an estimate of the maximum relative error one can incur by choosing to employ a particular welfare measure in place of the others.[4] [1] Cysne, R.P., Turchick, D., 2010. Welfare costs of inflation when interest-bearing deposits are disregarded: A calculation of the bias. Journal of Economic Dynamics and Control 34, 1015-1030. [2] Cysne, R.P., Turchick, D., 2009. On the integrability of money-demand functions by the Sidrauski and the shopping-time models. Journal of Banking & Finance 33, 1555-1562. [3] Cysne, R.P., Turchick, D., 2010. Money supply and capital accumulation on the transition path revisited. Journal of Money, Credit and Banking 42, 1173-1184. [4] Cysne, R.P., Turchick, D., 2011. An ordering of measures of the welfare cost of inflation in economies with interest-bearing deposits. Macroeconomic Dynamics, forthcoming.
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This work investigates the effects of inflation on income distribution. We use a dynamic shopping-time model to show that a differentiated access to transacting technologies by poor and rich consumers is enough to generate a positive link between inflation and the Gini coefficient of income distribution.
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Lucas (2000) has ShO\nl t hat Baile,\"'s formula for t hc \\'elfare costs of inflatioIl caIl bc rcgardpd as an approximation to t hc gcneral-equilibriuIll IllCaSllH'S \\"hich emerge from thc Sidrauski anrl the shopping-time models, In this paper \\'c shm\' that Baile~"s mcaSllrc can bc cxactly obtairlf'd in tllf' Siclrauski geIleral-equilibri1lIn framp\\'ork under the assUIllption of quasilinpar prefpreIlC'cs, The rpslllt. based on ",heter or not \\'Palt h pffpcts are incorporatccl into t hp analysis, is also helpful in darif\'ing \\'hy Lucas' Illeasurp clerin'd from the Siclrauski model turns 01lt to be aIl upper bOllIlcl to Bailp~"s, T,,'o eXaInplcs arp used to illustratc t he main C'ondusions,
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We study the optimal “inflation tax” in an environment with heterogeneous agents and non-linear income taxes. We first derive the general conditions needed for the optimality of the Friedman rule in this setup. These general conditions are distinct in nature and more easily interpretable than those obtained in the literature with a representative agent and linear taxation. We then study two standard monetary specifications and derive their implications for the optimality of the Friedman rule. For the shopping-time model the Friedman rule is optimal with essentially no restrictions on preferences or transaction technologies. For the cash-credit model the Friedman rule is optimal if preferences are separable between the consumption goods and leisure, or if leisure shifts consumption towards the credit good. We also study a generalized model which nests both models as special cases.
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This article provides new insight into how the ambience and design of shopping environments impact onspending behaviour. Environmental cues in a retail area influence emotional states of by-passers, which in turn influence spending levels. Past research suggested that this effect only applies to shops with moderate arousal level. Also, several studies failed to confirm a relationship between emotions and spending levels. This is surprising, since high arousal environments (e.g., amusement parks, sports stadiums and airports) often feature a wide range of retail outlets. Based on survey data collected in a live airport shopping area, this study finds a relationship between pleasure emotions associated with the retail area and recalled consumer spending, but also the time available for shopping (which in an airport is constrained). Also, visitors’ emotional state was influenced by the ambience (e.g., cleanliness, noise levels, lighting) as well as the design (e.g., easy wayfinding, seating areas) of the retail area. Shopper’s arousal levels did not explain variations in spending level. Implications for researchers and managers are discussed as well as suggestions for future research.
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L'utilisation de l'Internet comme medium pour faire ses courses et achats a vu une croissance exponentielle. Cependant, 99% des nouveaux business en ligne échouent. La plupart des acheteurs en ligne ne reviennent pas pour un ré-achat et 60% abandonnent leur chariot avant de conclure l'achat. En effet, après le premier achat, la rétention du consommateur en ligne devient critique au succès du vendeur de commerce électronique. Retenir des consommateurs peut sauver des coûts, accroître les profits, et permet de gagner un avantage compétitif.Les recherches précédentes ont identifié la loyauté comme étant le facteur le plus important dans la rétention du consommateur, et l'engagement ("commitment") comme étant un des facteurs les plus importants en marketing relationnel, offrant une réflexion sur la loyauté. Pourtant, nous n'avons pu trouver d'étude en commerce électronique examinant l'impact de la loyauté en ligne et de l'engagement en ligne ("online commitment") sur le ré-achat en ligne. Un des avantages de l'achat en ligne c'est la capacité à chercher le meilleur prix avec un clic. Pourtant, nous n'avons pu trouver de recherche empirique en commerce électronique qui examinait l'impact de la perception post-achat du prix sur le ré-achat en ligne.L'objectif de cette recherche est de développer un modèle théorique visant à comprendre le ré-achat en ligne, ou la continuité d'achat ("purchase continuance") du même magasin en ligne.Notre modèle de recherche a été testé dans un contexte de commerce électronique réel, sur un échantillon total de 1,866 vrais acheteurs d'un même magasin en ligne. L'étude est centrée sur le ré-achat. Par conséquent, les répondants sélectionnés aléatoirement devaient avoir acheté au moins une fois de ce magasin en ligne avant le début de l'enquête. Cinq mois plus tard, nous avons suivi les répondants pour voir s'ils étaient effectivement revenus pour un ré-achat.Notre analyse démontre que l'intention de ré-achat en ligne n'a pas d'impact significatif sur le ré-achat en ligne. La perception post-achat du prix en ligne ("post-purchase Price perception") et l'engagement normatif en ligne ("Normative Commitment") n'ont pas d'impact significatif sur l'intention de ré-achat en ligne. L'engagement affectif en ligne ("Affective Commitment"), l'attitude loyale en ligne ("Attitudinal Loyalty"), le comportement loyal en ligne ("Behavioral Loyalty"), l'engagement calculé en ligne ("Calculative Commitment") ont un impact positif sur l'intention de ré-achat en ligne. De plus, l'attitude loyale en ligne a un effet de médiation partielle entre l'engagement affectif en ligne et l'intention de ré-achat en ligne. Le comportement loyal en ligne a un effet de mediation partielle entre l'attitude loyale en ligne et l'intention de ré-achat en ligne.Nous avons réalisé deux analyses complémentaires : 1) Sur un échantillon de premiers acheteurs, nous trouvons que la perception post-achat du prix en ligne a un impact positif sur l'intention de ré-achat en ligne. 2) Nous avons divisé l'échantillon de l'étude principale entre des acheteurs répétitifs Suisse-Romands et Suisse-Allemands. Les résultats démontrent que les Suisse-Romands montrent plus d'émotions durant l'achat en ligne que les Suisse-Allemands. Nos résultats contribuent à la recherche académique mais aussi aux praticiens de l'industrie e-commerce.AbstractThe use of the Internet as a shopping and purchasing medium has seen exceptional growth. However, 99% of new online businesses fail. Most online buyers do not comeback for a repurchase, and 60% abandon their shopping cart before checkout. Indeed, after the first purchase, online consumer retention becomes critical to the success of the e-commerce vendor. Retaining existing customers can save costs, increase profits, and is a means of gaining competitive advantage.Past research identified loyalty as the most important factor in achieving customer retention, and commitment as one of the most important factors in relationship marketing, providing a good description of what type of thinking leads to loyalty. Yet, we could not find an e-commerce study investing the impact of both online loyalty and online commitment on online repurchase. One of the advantages of online shopping is the ability of browsing for the best price with one click. Yet, we could not find an e- commerce empirical research investigating the impact of post-purchase price perception on online repurchase.The objective of this research is to develop a theoretical model aimed at understanding online repurchase, or purchase continuance from the same online store.Our model was tested in a real e-commerce context with an overall sample of 1, 866 real online buyers from the same online store.The study focuses on repurchase. Therefore, randomly selected respondents had purchased from the online store at least once prior to the survey. Five months later, we tracked respondents to see if they actually came back for a repurchase.Our findings show that online Intention to repurchase has a non-significant impact on online Repurchase. Online post-purchase Price perception and online Normative Commitment have a non-significant impact on online Intention to repurchase, whereas online Affective Commitment, online Attitudinal Loyalty, online Behavioral Loyalty, and online Calculative Commitment have a positive impact on online Intention to repurchase. Furthermore, online Attitudinal Loyalty partially mediates between online Affective Commitment and online Intention to repurchase, and online Behavioral Loyalty partially mediates between online Attitudinal Loyalty and online Intention to repurchase.We conducted two follow up analyses: 1) On a sample of first time buyers, we find that online post-purchase Price perception has a positive impact on Intention. 2) We divided the main study's sample into Swiss-French and Swiss-German repeated buyers. Results show that Swiss-French show more emotions when shopping online than Swiss- Germans. Our findings contribute to academic research but also to practice.
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This article introduces EsPal: a Web-accessible repository containing a comprehensive set of properties of Spanish words. EsPal is based on an extensible set of data sources, beginning with a 300 million token written database and a 460 million token subtitle database. Properties available include word frequency, orthographic structure and neighborhoods, phonological structure and neighborhoods, and subjective ratings such as imageability. Subword structure properties are also available in terms of bigrams and trigrams, bi-phones, and bi-syllables. Lemma and part-of-speech information and their corresponding frequencies are also indexed. The website enables users to either upload a set of words to receive their properties, or to receive a set of words matching constraints on the properties. The properties themselves are easily extensible and will be added over time as they become available. It is freely available from the following website: http://www.bcbl.eu/databases/espal