Applications of graph algorithms in GIS

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When do Better Schools Raise Housing Prices? Evidence from Paris Public and Private Schools

In this paper, we investigate how housing prices react to the quality of education offered by neighbouring public and private schools. The organization of secondary schooling in the city of Paris, which combines residence-based-assignment to public schools with a well-developed and almost entirely publicly funded private school system, offers a valuable empirical context for analyzing how private schools affect the capitalization of public school performance in housing prices. Using comprehensive data on both schools and real estate transact ions over the period 1997-2004, we develop a matching framework to carefully compare sales across school attendance boundaries. We find that a standard deviation increase in public school performance raises housing prices by 1.4 to 2.4%. Moreover, we show that the capitalization of public school performance in the price of real estate shrinks as the availability of private schools increases in the neighbourhood. Our results confirm the predictions of general equilibrium models of school choice that private schools, by providing an advantageous outside option to parents, tend to mitigate the impact of public school performance on housing prices.School attendance zones, private schools, housing markets,residential segregation

Can experts interpret a map's content more efficiently?

This paper describes the statistical comparison of the results from an experiment with a ‘between user’-design. The first group of participants consists out of novices whereas the second group consists out of experts which have experience in map use and have had training in cartography. The same stimuli (twenty screen maps) are presented in a random order to the participants who have to locate a number of labels on the map image. The participants are asked to indicate when they located a name by a button action, resulting in a time measurement. Furthermore, the participant’s eye movements are registered during the whole test. The combined information reveals a same trend in the time intervals needed to locate the subsequent labels in both user groups. However, the experts are significantly faster in locating the names on the map (P<0.010). The recorded eye movements further confirm and explain this finding: the expert’s fixations are significantly shorter (P<0.001) and can consequently have more fixations per second (P<0.001). This means that an expert can interpret the map content more efficiently and can thus search a larger part of the map in the same amount of time

Analyzing eye movement patterns to improve map design

Recently, the use of eye tracking systems has been introduced in the field of cartography and GIS to support the evaluation of the quality of maps towards the user. The quantitative eye movement metrics are related to for example the duration or the number of the fixations which are subsequently (statistically) compared to detect significant differences in map designs or between different user groups. Hence, besides these standard eye movement metrics, other - more spatial - measurements and visual interpretations of the data are more suitable to investigate how users process, store and retrieve information from a (dynamic and/or) interactive map. This information is crucial to get insights in how users construct their cognitive map: e.g. is there a general search pattern on a map and which elements influence this search pattern, how do users orient a map, what is the influence of for example a pan operation. These insights are in turn crucial to be able to construct more effective maps towards the user, since the visualisation of the information on the map can be keyed to the user his cognitive processes. The study focuses on a qualitative and visual approach of the eye movement data resulting from a user study in which 14 participants were tested while working on 20 different dynamic and interactive demo-maps. Since maps are essentially spatial objects, the analysis of these eye movement data is directed towards the locations of the fixations, the visual representation of the scanpaths, clustering and aggregation of the scanpaths. The results from this study show interesting patterns in the search strategies of users on dynamic and interactive maps

A twisted spectral triple for quantum SU(2)

We initiate the study of a q-deformed geometry for quantum SU(2). In contrast with the usual properties of a spectral triple, we get that only twisted commutators between algebra elements and our Dirac operator are bounded. Furthermore, the resolvent only becomes compact when measured with respect to a trace on a semifinite von Neumann algebra which does not contain the quantum group. We show that the zeta function at the identity has a meromorphic continuation to the whole complex plane and that a large family of local Hochschild cocycles associated with our twisted spectral triple are twisted coboundaries.Comment: 14 page

In brief... House Prices and School Quality: Evidence from State and Private Education in Paris

It is now widely understood that the quality of state schools in a neighbourhood has an impact on local house prices. Analysing data for Paris, Gabrielle Fack and Julien Grenet have looked deeper into this link by exploring how the presence of private schools influences parents' willingness to pay to live near good state schools.School catchment areas, France, private education, public education, housing, house prices

Why Are Low-Income Households Paying Increasingly High Rents? The Effect of Housing Benefit in France (1973-2002)

Since the late 1970s, means-based rent assistance has become the main housing policy instrument to the detriment of building subsidies. Yet the development of this assistance has gone hand in hand with an increase in the cost of housing for the most disadvantaged tenant households. We seek to evaluate the impact of this on the increase in rents for low-income households. The early-1990s reform of the extension of assistance constitutes a natural experiment whereby the effects of housing benefits can be isolated, since it was applied solely to certain types of households and not others. We use data from the INSEE Housing surveys to show that the assistance could well have a lot to do with the increase in rents per square metre for low-income households. The estimates obtained show that 50% to 80% of the housing benefit received by these households has been absorbed by increases in their rents.Housing Benefit, Subsidy Incidence