Relaxed gravity models, that is, gravity models with upper and lower bounds on the marginal totals, often have solutions with the property that the upper or lower bounds are satisfied with equality for most marginal totals. In this paper modifications are presented for the relaxed gravity models, which overcome this unwanted model property. The paper contains illustrative examples with data from the county of Östergötland, Sweden.
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References
1.
DaceyM PNorcliffeA, 1977, “A flexible doubly-constrained trip distribution model”Transportation Research11203–204
2.
ErlanderS, 1980Lecture Notes in Economics and Mathematical Systems 173“Optimal spatial interaction and the gravity model” (Springer, Berlin)
3.
ErlanderS, 1981, “Entropy in linear programs”Mathematical Programming21137–151
4.
JeffersonT RScottC H, 1979, “The analysis of entropy models with equality and inequality constraints”Transportation Research13B123–132
5.
JörnstenK, 1979, “A relaxed distribution model and its combined distribution and assignment counterpart” TR LiTH-MAT-R-79-38, Department of Mathematics, Linköping Institute of Technology, Sweden
LebeufRStewartN FJörnstenK, 1981, “On the use of Bregman's balancing method for the solution of relaxed distribution problems”Environment and Planning A13267–271