期刊名称：Journal of Artificial Societies and Social Simulation
印刷版ISSN：1460-7425
出版年度：2015
卷号：18
期号：2
页码：1-24
DOI：10.18564/jasss.2768
出版社：University of Surrey, Department of Sociology
摘要：Iterative Proportional Fitting (IPF), also known as biproportional fitting, 'raking' or the RAS algorithm, is an established procedure used in a variety of applications across the social sciences. Primary amongst these for urban modelling has been its use in static spatial microsimulation to generate small area microdata – individual level data allocated to administrative zones. The technique is mature, widely used and relatively straight-forward. Although IPF is well described mathematically, accessible examples of the algorithm written in modern programming languages are rare. There is a tendency for researchers to 'start from scratch', resulting in a variety of ad hoc implementations and little evidence about the relative merits of differing approaches. These knowledge gaps mean that answers to certain methodological questions must be guessed: How can 'empty cells' be identified and how do they influence model fit? Can IPF be made more computationally efficient? This paper tackles these questions and more using a systematic methodology with publicly available code and data. The results demonstrate the sensitivity of the results to initial conditions, notably the presence of 'empty cells', and the dramatic impact of software decisions on computational efficiency. The paper concludes by proposing an agenda for robust and transparent future tests in the field.
关键词：Microsimulation; Iterative Proportional Fitting; Deterministic Reweighting; Population Synthesis; Model Testing; Validation
