The Analysis of Spatial Association by Use of Distance Statistics

Introduced in this paper is a family of statistics, G, that can be used as a measure of spatial association in a number of circumstances. The basic statistic is derived, its properties are identified, and its advantages explained. Several of the G statistics make it possible to evaluate the spatial association of a variable within a specified distance of a single point. A comparison is made between a general G statistic and Moran's I for similar hypothetical and empirical conditions. The empirical work includes studies of sudden infant death syndrome by county in North Carolina and dwelling unit prices in metropolitan San Diego by zip-code districts. Results indicate that G statistics should be used in conjunction with I in order to identify characteristics of patterns not revealed by the I statistic alone and, specifically, the G_i and G_i* statistics enable us to detect local “pockets” of dependence that may not show up when using global statistics.     

Defining “Official” Built Heritage Discourses within the Irish Planning Framework: Insights from Conservation Planning as Social Practice

Conservation of built heritage is a key planning process and goal which shapes urban development outcomes across European cities. In Ireland, conservation of the built heritage is a key part of the planning framework, albeit one that is, in comparative terms, only recently established. While it is widely recognized that the underlying rationale for conservation of built heritage varies considerably (from cultural priorities to place marketing), the literature suggests that heritage and conservation professionals perform a key role in controlling decision-making through an official or “authorized” heritage discourse (AHD), emphasizing expert values and knowledge and based around selective heritage storylines often reflecting elite tastes. Drawing on policy and practice in Ireland, in this paper, we contribute to these debates by further unpacking the AHD, exploring tensions within the heritage policy elite through examination of competing views and representations relating to the purpose of built heritage protection. Based on a discourse analysis following interviews with key national actors, we identify two key narratives—a “museum-curatorial” discourse and an “inclusive heritage” discourse—which in turn frame conservation practices. We argue that subtle variations of heritage meanings have the potential to either reproduce (museum-curatorial discourse) or challenge (inclusive heritage discourse) conventional modes of practice, particularly relating to the relationship between built heritage and identity and the role of public engagement.