SPATIAL FLOWS AND SPATIAL PATTERNS
SPATIAL FLOWS AND SPATIAL PATTERNS
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DOI：
10.1068/a160529
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发表时间：
1984-01-01
期刊：
影响因子：
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通讯作者：
FOTHERINGHAM, AS
中科院分区：
文献类型：
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作者：
FOTHERINGHAM, AS
作者最近描述了重力空间相互作用模型的错误描述。这种错误规范导致的参数估计偏差似乎会在估计的距离衰减参数中产生“地图模式效应”或“空间结构偏差”。本文进一步探讨了重力参数估计中的错标偏差。偏差的严重程度以可预测的方式随空间结构的变化而变化。特别是，这种偏差取决于空间系统中存在的可达性模式。在城市内和城市间（或区域间）流动矩阵中讨论了这种模式的相关方面。它表明，从一个空间系统的中心的空间结构的检查是可能的，先验地，确定是否显著偏差将出现在一个重力模型的校准。从理论上讲，某些中心的构型会产生最大的偏置。因此，作者回答了这个问题，“为什么重力参数的估计在某些系统中似乎是有偏差的，而在其他系统中却没有？”
The misspecification of gravity spatial interaction models has recently been described by the author. The bias in parameter estimates that results from such misspecification appears to produce the ‘map pattern effect’ or ‘spatial structure bias’ in estimated distance-decay parameters. A further aspect of the misspecification bias in gravity parameter estimates is explored here. The severity of the bias is shown to vary in a predictable manner with variations in spatial structure. In particular, the bias is shown to be dependent upon the pattern of accessibility that exists within a spatial system. The relevant aspects of this pattern are discussed for intraurban and interurban (or interregional) flow matrices. It is shown that from an examination of the spatial structure of centres in a spatial system it is possible, a priori, to identify whether significant bias will arise in the calibration of a gravity model. Certain configurations of centres are shown theoretically to produce maximal bias. The author thus answers the question, “why do gravity parameter estimates appear to be biased in some systems but not in others?”