Search results

The main purpose of this paper is to determine the discount function which better fits the individuals' preferences through the empirical analysis of the different functions used in the field of intertemporal choice.

After an in-depth revision of the existing literature and unlike most studies which only focus on exponential and hyperbolic discounting, this manuscript compares the adjustment of data to six different discount functions. To do this, the analysis is based on the usual statistical methods, and the non-linear least squares regression, through the algorithm of Gauss-Newton, in order to estimate the models' parameters; finally, the AICc method is used to compare the significance of the six proposed models.

This paper shows that the so-called q-exponential function deformed by the amount is the model which better explains the individuals' preferences on both delayed gains and losses. To the extent of the authors' knowledge, this is the first time that a function different from the general hyperbola fits better to the individuals' preferences.

This paper contributes to the search of an alternative model able to explain the individual behavior in a more realistic way.

As the demand for online auctions increases, the process of monitoring multiple auction houses, deciding which auction to participate in and making the right bids, become challenging tasks for consumers. Hence, knowing the closing price of a given auction would be an advantage, since this information will ensure a win in a given auction. However, predicting a closing price for an auction is not easy, since it is dependent on many factors. The purpose of this paper is to report on a predictor agent that utilises grey system theory to predict the closing price for a given auction.

The focus of the research is on grey system agent. This paper reports on the development of a predictor agent that attempts to predict the online auction closing price in order to maximise the bidder's profit. The performance of this predictor agent is compared with two well‐known techniques, the Simple Exponential Function and the Time Series, in a simulated auction environment and in the eBay auction.

The grey theory agent gives a better result when less input data are made, while the Time Series Agent can be used with the availability of a lot of information. Although the Simple Exponential Function Agent is able to predict well with less input data, it is not an appropriate method to be applied in the prediction model since its formula is not realistic and applicable in predicting the online auction closing price. The experimental results also showed that using moving historical data produces a higher accuracy rate than using fixed historical data for all three agents.

Grey system theory prediction model, GM(1, 1) has not been applied in online auction prediction. In this paper the authors have applied grey theory into an agent to predict the closing price of an online auction, in order to increase the profit of bidders in the bidding stage. The experimental results show that the accuracy of the grey prediction model is more then 90 per cent, with less then eight historical data inputs.

Points out that differences in the background of the working population, are often made responsible for the observed inequality of income distribution. Explores whether the observed distribution in incomes in countries such as the Federal Republic of Germany (West and East), Great Britain, Sweden, the United States and Brazil could not be the result of a statistical distribution process in which households participate. Recalls the early work in statistical thermodynamics by Boltzmann and Maxwell, who studied the distribution of energy among an ensemble of identical molecules, and which showed that not all molecules hold the same energy, but rather that the distribution has an exponential fall‐off character, with most molecules being in the lower energy bracket. Adapts the Maxwell‐Boltzmann distribution to incomes, and transforms these distributions into well‐known Lorenz graphs, and obtains a perfect match for each examined country. Suggests that, as the distributions can be directly related to their corresponding statistical weights, and as their logarithms are proportional to entropy in statistical thermodynamics, it could be shown that the unequal income distribution has a higher entropy, and therefore is more stable than the corresponding low entropy distribution resulting from Boulding′s principle of equal advantage where all households earn the same income. Supposes that neither of the two extreme stand‐points to explain the inequality of incomes can lead to a totally satisfactory explanation. Proposes that evolutionary strategies may be an interesting lead to follow up in more detail.

The purpose of this paper is to introduce the main measures of inconsistency in the context of intertemporal choice and to identify the relationships between them (more specifically, the measures by Prelec, Takahashi and Rohde). In effect, Thaler (1981), awarded the Nobel Prize in Economics 2017, argued that when a preference must be expressed between two reward options, some people may reverse their original preference when a significant delay is introduced before the reward is to be received. This anomaly is known as inconsistency in intertemporal choice.

After a revision of the existing literature and by using the methods from mathematical calculus, the authors have derived the logical relationships between the measures presented in this paper.

The main contribution of this paper is the proposal of a novel parameter, the so-defined ratio of two instantaneous discount rates, which the authors call the instantaneous variation rate, which allows relating some other measures of inconsistency, namely the measures described by Prelec and Rohde. A limitation of this paper is the unavailability of empirical information about the inconsistency measures needed to substantiate the theoretical findings. Indeed, this paper has social implications because recent behavioral and neuroeconomic studies have shown the existence of preference reversal or time inconsistency in other areas. The authors’ models can be implemented in these fields in order to better analyze the situations of inconsistency.

The originality of this paper lies in the authors’ aim to bring some order to the proposed measures of inconsistency which have arisen as a result of the different approaches adopted.

A method of defining the filtration efficiency of filter media has been devised, in which the transmission factor at a specified size is measured instead of the effective cut‐off size. The new measure is more sensitive and provides a more useful fiure than the old measure of effective cut‐off size. An additional test is proposed to measure the efficiency of removal of particles of smaller sizes; this test requires the derivation of the transmission curve, which is defined. No change is proposed in the method of measurement of flow efficiency in terms of flow constant. It is suggested that the specification of a fine particle filter medium should include the following clauses: (a) A statement of the maximum acceptable transmission factor at a given size (cither 5 microns or 10 microns). (b) A statement of the maximum acceptable transmission factors at various smaller sizes. (c) A statement of the minimum acceptable flow constant. Experimental techniques, including the method of preparing the artificial contaminants, are described. Results are presented on nine materials and a comparison is made for five of these materials between transmission factors at 5 microns and 10 microns and effective cut‐off sizes. The dependence of transmission factor and flow constant on thickness of filter medium is discussed.

The size and number of employment subcenters have increased in large metropolitan areas as the spatial distribution of jobs has become increasingly decentralized. Although employment decentralization is not a new phenomenon, only recently have concentrations of employment outside the central city begun to rival the traditional central business district (CBD) in size and scope. Because of this change, neither theoretical nor empirical models in urban economics now rely solely on the traditional monocentric city model of Muth (1969) and Mills (1972). Instead, recent research incorporates some version of a polycentric model, a trend that Anas et al. (1998) document in their excellent review article.

BEFORE a detailed consideration of internal stresses may be made, it is necessary to define external loadings which are possibly critical. This involves the consideration of manoeuvres throughout the altitude range of the aeroplane, to a severity fixed by aerodynamic or specification values of speed and normal acceleration.

THIS year marks the centenary of the publication of the most significant paper every written in the field of tribology. It is therefore timely to recall the nineteenth century developments in mechanical engineering science which prompted Osborne Reynolds to undertake his studies of fluid‐film lubrication, to consider the essence of his contribution, to review one hundred years of further progress and to comment on the current position.

The purpose of this paper is to analyze whether urban tourism attractiveness affects young adult migration within Germany. Currently, factors like urban attractiveness, environmental qualities or vicinity to amenities play a more important role for the migration of young adults than in the past. This has highly asymmetric implications for the housing (and commercial real estate) markets in cities with an abundance of urban attractiveness, compared to cities without such attractions.

This analysis focuses on the internal migration of young adults (18-30-year-olds). First, some stylized facts regarding migration patterns are presented by means of descriptive and cluster analyses (k-means methodology) with respect to the net immigration rate for the two years, 2004 and 2014. Second, ordinary least squares-regression analyses are used to estimate the connection between urban tourism attractiveness and migration.

Young adults in Germany predominantly migrate to cities. The authors find typical migration patterns, and the regression results indicate that young adult migration is highly correlated with the indicator measuring urban tourism attractiveness. This means that urban attractions matter for young adults. Finally, the authors also find that housing rents are correlated with urban tourism attractiveness.

Good city planning must not only be concerned with new industrial sites, but also about esthetic neighborhoods and, for example, attractive squares. Moreover, because city structures and urban amenities are both path dependent and expensive to change, it is likely that the winning cities of today will remain winners in the next decade, which is good news for risk-averse investors.

To the best of the authors’ knowledge, the paper provides the first empirical analysis of the connection between urban tourism attractiveness and the migration of young adults, in the context of German cities.

Summarises six key papers presented at the Sensor and Transducer Conference, Birmingham, UK, 14‐15 February 2001. Features gas and chemical sensors using laser ring‐down, and photo acoustic, effects as well as wave guides and Bragg gratings. Also discusses self‐powered sensors, micro‐electromechanical systems and fibre optic sensors.