Defining spatial housing submarkets: Exploring the case for expert delineated boundaries

Although there are numerous reasons for real estate analysts to construct spatial housing submarkets, there is little clarity about how this might best be done in practice. The existing literature offers a variety of techniques including those based on principal components analysis, cluster analysis and a range of other statistical procedures. This paper asks whether, given their market expertise and their role in disseminating information, shaping search patterns and informing bid formation, real estate agents might offer an effective but less data intensive method of submarket construction. The empirical research is based on an experiment that compares the predictive of different sets of submarket boundaries constructed by using either standard statistical methods or through consultation with real estate agents and other market analysts. The analysis draws on housing transactions data from Istanbul, Turkey. While the results do not demonstrate the outright superiority of any single method, they do suggest that expert-defined boundaries tend to perform at least as well as alternative construction techniques. Importantly, the results suggest that agent-based methods for delineating submarket boundaries might be used with a degree of confidence by real estate analysts and planners in market contexts where rich micro-datasets are not readily available. This has been one of the constraints internationally on wider adoption of submarket boundaries as an analytical tool

Synthesis and structural characterisation of various organosilane-organogermane and organosilane-organostannane statistical copolymers by the Wurtz reductive coupling polymerisation: Sn-119 NMR and EXAFS characterisation of the stannane copolymers

A number of polysilane-based copolymers with organogermanes and organostannanes have been prepared by the Wurtz-type reductive coupling of the corresponding dichlorodiorgano group 14 precursors. The copolymers synthesised were poly(di-n-butylgermane-c-o-methylphenylsilane), poly(di-n-butylgermane-co-n-hexylmethylsilane), poly(di-nbutylstannane-co-methylphenylsilane) and poly(methylphenylsilane-co-diphenylgermane). Poly(di-n-butylsilane) and poly(di-n-butylgermane) were also synthesised by the room temperature polymerisation of the dichloro-precursors in THF at room temperature and obtained in the highest reported yields to date from a Wurtz-type polymerisation. The polymers and copolymers were characterised by H-1, C-13, Si-29 and Sn-119 NMR spectroscopy and UV-vis spectroscopy. The Si-29 and Sn-119 NMR spectroscopic data provided unambiguous evidence for the incorporation of germane and stannane units into the predominantly polysilane backbones. The Sn-119 analysis is the first reported for such copolymers. UV-vis spectroscopy demonstrated that increasing the molar ratios of stannane:silane in the final copolymer led to a red-shift in the observed broad absorption peak. One of the organosilane-organostannane copolymers (PMPS-co-BuSn 2) was analysed by extended X-ray absorption fine-structure spectroscope (EXAFS) and X-ray absorption near-edge spectroscopy (XANES). Bond lengths were obtained for Sn-Sn (2.82 angstrom), Sn-Si (2.58 angstrom) and Sn-C (2.15 angstrom) and they correspond to those expected for Sri based compounds

Solution DFWM chi((3)) non-linear optical properties of poly[(arylene)silylene]s and poly[(arylene)(ethynylene)silylene]s containing tetra- or hypercoordinate silicon

The third-order optical nonlinearities of a series of conjugated poly[(arylene)(ethynylene)silylene]s, and also of a complementary series of poly[(arylene)silylene] statistical copolymers without acetylene groups, have been studied in chloroform solution by using the degenerate four-wave mixing technique with a Q-switched Nd:YAG laser-oscillator at 1064 nm and a pulse duration of ca. 6 ns. The polymers contain a variety of arylene groups including carbazole and anthracene. The electronic and nuclear contributions of the chi((3)) susceptibility and the thermal nonlinearity of the solutions were separated. The chi((3)) susceptibilities of some poly[(arylene)(ethynylene)silylene]s were found to be as high as \Re chi((3))\=0.95x10(-10) esu for solutions of concentration 50 g l(-1). The results show that the presence of a single 8-(dimethylamino)naphthyl ligand at silicon affording pentacoordination has a beneficial effect on the chi((3)) properties. Comparison of the results for the poly[(arylene)silylene]s with those for the poly[(arylene)(ethynylene)silylene]s suggests that the absence of acetylene groups in the former case has in general a deleterious effect on the chi((3)) properties. Confirmation of the order of magnitude of the non-linear response has been confirmed by Z-scan measurements with picosecond laser pulses on hybrid sol-gel silica films of two of the poly[(arylene)(ethynylene)silylene]s containing arylene amide groups

Spatial effects in regional tourism firm births and deaths

Agglomeration economies are benefits that firms obtain when they locate close to one another or are constrained spatially. Tourism is heavily reliant on agglomeration economies rather than mere resource endowments. Policy formation requires an understanding of how tourism agglomeration impacts entrepreneurship within regions. In this chapter, we focus on how agglomeration economies impact enterprise birth and death rates within the tourism sector in Ireland using a comprehensive dataset on tourism firm births and deaths. Agglomeration economies have been studied in the area of regional economic growth and prosperity, but less is known about the extent to which spatial agglomeration economies affect regional firm births and deaths in the tourism sector. Our results provide evidence of positive spatial dependence in regional tourism enterprise births and deaths. Co-location of a diverse set of complementary enterprises fosters greater tourism enterprise births. Greater local specialisation rather than diversity lowers regional tourism enterprise deaths

Compositional and urban form effects on residential property value patterns in Greater London

The objective of this research is to determine the role of urban street layout design in the process of shaping property values. The effect of spatial accessibility on rent is a classic finding of spatial economics. Using space syntax fine-grained spatial design analysis, which indexes the spatial centrality and accessibility, the patterns of property prices are analysed for a large contiguous sample of over 60 000 residential dwellings in a North London borough, using the council tax band as a proxy variable for the property price. Few studies have examined the effect of spatial contiguity on the housing sub-market classification. The findings demonstrate that the council tax band proxy is a good indicator of residential property sale prices. In addition, a hedonic model framework shows that spatial centrality and accessibility, as indexed by the space syntax spatial design analysis, accounts for the variations in residential property values for single and multiple dwellings when controlling for the property size, relative density and building age. Multivariate analysis is used to establish the weighting of the different variables. The single most important spatial factor is the property size, followed by the ambient density, the local and global spatial accessibility and the building age. Non-residential land use location, the proximity to main arterial roads and the associated traffic and air pollution are shown to inhibit the residential property location