Nonparametric Estimation of the Spatial Connectivity Matrix Using Spatial Panel Data

We use moments from the covariance matrix for spatial panel data to estimate the parameters of the spatial autoregression model, including the spatial connectivity matrix W. In the unrestricted spatial autoregression model, the parameters are underidentified by one when W is symmetric. We show that a special case exists in which W is asymmetric and its parameters are exactly identified. If the panel data are stationary and ergodic, spatially and temporally, the estimates of W and the spatial autoregression coefficients are consistent. Spatial panel data for house prices in Israel are used to illustrate this methodology. Los autores usan momentos de una matriz de covarianza para datos panel espaciales para estimar los parámetros del modelo de autoregresión espacial (spatial autoregressive model), incluyendo la matriz de conectividad (o de ponderación) espacial W. En el modelo de autoregresión espacial sin restricciones, los parámetros están sub‐identificados por un valor de uno en los casos que la matriz W es simétrica. Los autores demuestran que existe un caso especial en el cual la matriz W es asimétrica y sus parámetros tienen cálculo exacto. Si los datos panel son estacionarios y ergódicos, espacial y temporalmente, los estimados de W y el coeficiente de autoregresión espacial son consistentes. Para ilustrar la metodología propuesta, los autores usan datos‐panel espaciales de precios de vivienda en Israel. 本文通过采用空间面板数据的协方差矩阵对包含空间相关矩阵W的空间自回归模型进行参数的矩估计。在无约束空间自回归模型中,W是对称矩阵时,参数可由其估计得到。本文展示了一种W是对称矩阵且其参数能够被精确估计的特殊情况。如果面板数据在时间与空间特征上具有平稳性和遍历性,那么W和空间自回归参数的估计是一致的。最后,针对以色列住房价格的空间面板数据采用此方法进行实证研究。     

Industry Influence in Stakeholder‐Driven State Climate Change Planning Efforts

Drawing from the literature on public participation and stakeholder collaboratives, this article investigates the influence of power and wealth, as well as political and economic context on the output of stakeholders advisory committees convened to formulate state greenhouse gas (GHG) mitigation policies. Using small sample regression techniques, we analyze the outputs of stakeholder groups in 18 states that have completed Climate Action Plans to reduce GHGs. We find that an increase of 1 percent in the number of energy industry representatives that participate in Climate Action Councils significantly predicts a 4 percent reduction of GHG mitigation targets for the energy sector. More surprisingly, the results also show that where the utilities represent a larger share of the state economy, the Climate Action Plans identify more aggressive GHG reduction goals for the energy sector. We also find that the political orientation of the executive of the state is not correlated with GHG mitigation requirements for the energy sector, suggesting that GHG mitigation is less partisan at the state level than in Washington, DC. We find no evidence that state wealth is associated with GHG mitigation requirements. Finally, we suggest additional research needed to clarify the role of stakeholder participation processes in the evolving arena of climate change policy.     

Geochemical impacts to prehistoric iron-rich siliceous artifacts in the nearshore coastal zone

In the Middle Atlantic region of the United States, landscapes drowned by sea level rise contain scores of prehistoric archaeological sites. These sites provide archaeologists with a rare opportunity to investigate various geologic processes. During the transition from a terrestrial to an offshore setting, the materials associated with an archaeological site are exposed to a series of geochemical processes inherent to the formation of tidal marsh. The duration of the geochemical exposure to tidal marsh is largely dependent on the rate of marine transgression. Here we describe the stages associated with the sulfidization and sulfuricization scheme and the impact to iron-rich lithic artifacts from naturally drowned archaeological sites. Sulfidization and sulfuricization should also impact buried archaeological materials as a result of anthropogenic dredge spoil dumping and the creation of man-made tidal marshes along modern coastlines. Our results indicate that the surfaces of an iron-rich artifact, as well as its interior are visually and geochemically altered by prolonged exposure to the anaerobic conditions of a tidal marsh. Not only should researchers be cautious about making lithic material identification on artifacts found within coastal tidal marsh areas, but museum curators should be aware of the damaging impact of long-term aerobic storage. The geochemical tidal marsh scheme that has altered or corroded iron-rich lithic artifacts in the nearshore zone is an expression of a process that has impacted numerous earlier prehistoric sites currently located on the continental shelf or beneath the coastal estuaries around the world.     

Michael Oakeshott’s Theological Genealogy of Political Modernity

This essay attempts to provide a historical account of Michael Oakeshott’s famous distinction between civil and enterprise association. As such, it demonstrates that Oakeshott’s political skepticism and his concomitant view of civil association can in part be explained by his reliance on Augustinian theology. In a similar vein, Oakeshott’s linkage of enterprise association with the rationalism of Bacon must be considered in terms of Oakeshott’s understanding of Pelagianism and Gnosticism. Unsurprisingly, it will be demonstrated that despite Oakeshott’s disagreements with the political philosopher Eric Voegelin, he was very impressed by Voegelin’s work on the Gnostic origins of modernity. Consequently, a major claim of this essay is that Oakeshott’s speculative understanding of modern political thought constitutes a theological genealogy of political modernity in all but name.     

Towards a Multi-Agent-Based Modelling of Obsidian Exchange in the Neolithic Near East

This paper examines an alternative approach to previously proposed models of prehistoric exchange such as the law of monotonic decrement or the down-the-line exchange model developed by Renfrew (Proceedings of the Prehistoric Society 34: 319–331, 1968, Renfrew 1977) to explain the distribution of obsidian across the Near East during the Neolithic period. Renfrew’s down-the-line model, which results in a very regular and clustered network, does not permit the circulation of obsidian to regions of the Near East that are further than 300 km from the source zones, as is shown in the archaeological data available. Obsidian exchange is a complex system where multiple factors interact and evolve in time and space. We therefore explore Agent-Based Modelling (ABM) so as to get a better understanding of complex networks. ABM simulations of an exchange network where some agents (villages) are allowed to attain long-distance exchange partners through correlated random walks are carried out. These simulations show what variables (population density, degree of collaboration between villages…) are relevant for the transfer of obsidian over long distances. Moreover, they show that a type of small-world exchange network could explain the breadth of obsidian distribution (up to 800 km from source) during the Near Eastern Neolithic.