title: An extension of the formula for spreading speeds.
abstract: A well-known formula for the spreading speed of a discrete-time recursion model is extended to a class of problems for which its validity was previously unknown. These include migration models with moderately fat tails or fat tails. Examples of such models are given.
authors.affiliation: School of Mathematics, University of Minnesota, Minneapolis, Minnesota 55455, United States. hfw@math.umn.edu
authors.forename: Hans F
authors.initials: HF
authors.lastname: Weinberger
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Zhao
mesh_terms: D004641:Emigration and Immigration; D008954:Models, Biological