Generating synthetic baseline populations from register data

The paper presents a population synthesiser based on the method of Iterative Proportional Fitting (IPF) algorithm developed for the new Danish national transport model system. The synthesiser is designed for large population matrices and allows target variables to be represented in several target constraints. As a result, constraints for the IPF are cross-linked, which makes it difficult to ensure consistency of targets in a forecast perspective. The paper proposes a new solution strategy to ensure internal consistency of the population targets in order to guarantee proper convergence of the IPF algorithm. The solution strategy consists in establishing a harmonisation process for the population targets, which combined with a linear programming approach, is applied to generate a consistent target representation. The model approach is implemented and tested on Danish administrative register data. A test on historical census data shows that a 2006 population could be predicted by a 1994 population with an overall percentage deviation of 5-6% given that targets were known. It is also indicated that the deviation is approximately a linear function of the length of the forecast period.     

Cycling culture and socialisation: modelling the effect of immigrant origin on cycling in Denmark and the Netherlands

This paper focusses on travel socialisation by examining the effect of immigrant origin on cycling in two distinct European cycling cultures: Denmark and the Netherlands. Based on data from both countries’ national travel surveys, the empirical analyses show that people of immigrant origin cycle less compared to natives. While in Denmark this effect is significant only for people of non-Western origin, in the Netherlands it is also true for people of Western origin, probably because they originate to a greater extent from non-European countries (e.g., Indonesia). In the Netherlands, the effect of non-Western origin is larger for women than for men, while we do not find a significant gender interaction in the Danish data. Individuals with residence in neighbourhoods with a higher share of people of non-Western origin are less likely to cycle, probably as the national norm to cycle is less salient here. The results cannot be fully explained by differences in socioeconomic status, car access, or level of urbanisation. We assume that cultural norms mediated by parents play a relevant role. The results lend support to policies focused on stimulating the use of the bicycle among immigrants and especially women of non-Western origin.