“gravity model”的概念、定义、翻译、参考文献-科学参考

gravity model

Statistics

A model of spatial mobility. If locations i and j, at a distance d_ij apart, have populations p_i and p_j respectively, then the gravity model states that the number of individuals moving from i to j is proportional to p_i^a p_j^b d_ij^c, where a, b, and c are constants.

Geography

In human geography, gravity models evaluate, or forecast, the spatial interactions of goods, people, and so on, between origins and destinations. ‘The gravity model assumes that the probability of patronizing a facility (facility utility) is proportional to the attractiveness of the facility and inversely proportional to a function of the distance’ (Drezner and Drezner (2006) Geog. Analys. 38, 4). These interactions are expressed as:
$I_{i j} = k M_{i} M_{j} D i s t_{i j}^{- β}$
where I_ij denotes the interaction between two locations i and j; M_i and M_j represent the ‘masses’ measuring the strength of i and j (usually the population numbers of two settlements); Dist_ij stands for the distance between i and j; and k and β‎ are constants (G. Robinson 1998). ‘While the gravity model is now accepted by economics as a useful tool (it is said to be all over the place at the International Monetary Fund), it is considered only in an incidental manner in economic analysis that employs it’ (Isard (2001) Int. Reg. Sci. Rev. 24, 3). See Rodríguez-Pose and Zademach (2006) Tijdschrift 97, 3 on the gravity model, and mergers and acquisitions.

Economics

The theory that the contact between different locations is ruled by an inverse square law, similar to that governing gravitation. A consumer’s custom, for example, is divided between possible shopping centres in proportion to 1/x_i², where x_i is the distance to centre i. This model has also been applied to explain the patterns of international trade between countries.

单词	gravity model
释义	gravity model Statistics A model of spatial mobility. If locations i and j, at a distance d_ij apart, have populations p_i and p_j respectively, then the gravity model states that the number of individuals moving from i to j is proportional to p_i^a p_j^b d_ij^c, where a, b, and c are constants. Geography In human geography, gravity models evaluate, or forecast, the spatial interactions of goods, people, and so on, between origins and destinations. ‘The gravity model assumes that the probability of patronizing a facility (facility utility) is proportional to the attractiveness of the facility and inversely proportional to a function of the distance’ (Drezner and Drezner (2006) Geog. Analys. 38, 4). These interactions are expressed as: $I_{i j} = k M_{i} M_{j} D i s t_{i j}^{- β}$ where I_ij denotes the interaction between two locations i and j; M_i and M_j represent the ‘masses’ measuring the strength of i and j (usually the population numbers of two settlements); Dist_ij stands for the distance between i and j; and k and β‎ are constants (G. Robinson 1998). ‘While the gravity model is now accepted by economics as a useful tool (it is said to be all over the place at the International Monetary Fund), it is considered only in an incidental manner in economic analysis that employs it’ (Isard (2001) Int. Reg. Sci. Rev. 24, 3). See Rodríguez-Pose and Zademach (2006) Tijdschrift 97, 3 on the gravity model, and mergers and acquisitions. Economics The theory that the contact between different locations is ruled by an inverse square law, similar to that governing gravitation. A consumer’s custom, for example, is divided between possible shopping centres in proportion to 1/x_i², where x_i is the distance to centre i. This model has also been applied to explain the patterns of international trade between countries.
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