What Could a Lifestyle Model Look Like?
Peter Davidson, Peter Davidson Consultancy, Helen Porter, Peter Davidson Consultancy, Oliver Capon, Peter Davidson Consultancy
This paper builds on past ETC seminars which explored this question and concluded that ‘Lifestyle’ models were the way to go in Europe. This paper refines the concept and turns it into a model design which can be used for practical modelling.
Politicians are interested in delivering a better quality of life to their electorate including a higher income or better job, security, home, schooling, prospects for their children, happiness and a generally better quality of life. Over time people could take every opportunity to improve their lifestyle and this should be quantified so government policy, transport schemes and initiatives could be orientated to improve people’s lifestyle over time. All these individual lifestyle improvements add up to a happier electorate.
This would be modelled by a Lifestyle model which would model the accumulation of lifestyle improvements people make over time when they get a better job with more income, perhaps closer to home or when they move to a better house or school with better job prospects for their children or when they move to the countryside (or into the city) to be happier or when the home-minder gets a job (or gives up their job to be with the children).
The lifestyle model would be focussed on each household’s individual person so there would be a population synthesiser to synthesise the base year population and the households they are in, together with the variables needed in the model. This base year population would be input to the lifestyle model. The lifestyle model would have two components the lifestyle forecaster and the lifestyle generator. The lifestyle forecaster would predict the base year population forward to the forecast year modelling the changes in home, quality of life, employment, jobs, schooling, security and economy over time in increments of (say) 1 year up to the forecast year. The resulting forecast population would be given to the lifestyle generator which would model the other lifestyle patterns such as shopping, leisure, personal business and other activities and output a set of activities. These activities would be passed to the activity based model which would model activity scheduling and tour generation and thence on to usual tour choice hierarchy of tour main mode, destination, intermediate destination(s) assignment so as to provide the usual link and route based traffic, ridership and revenue outputs. They would also provide additional outputs on the lifestyle improvements attributed to the transport intervention.
Of these the Lifestyle model, comprising the lifestyle forecaster and lifestyle generator, are the new models which replace the activity generator in an otherwise ABM type of model architecture. In addition two extra terms would be added to the utility functions of the other models wherever necessary, which would account for the utility of the activity and the utility of the improved lifestyle associated with the choice. The idea being that a person travels to undertake an activity so the utility of undertaking the activity is higher than the disutility of the travel. Doing an activity such as working can accumulate additional utility such as happiness, money or buying a high-value possession which are ‘banked’ into one’s ‘lifestyle bank’. People accumulate their lifestyle bank during their lifetime by getting a better house, job, schooling for their children or accumulating wealth. These all affect their decisions – especially their long term decisions.
Modelling lifestyles will draw on cohort survival models for population forecasting and agent based land use and economic models for moving house, job or school where organisations, government etc would also be ‘agents’ comprised of people agents. This would need to be supplemented with additional research which would need to be undertaken. This research can use market research to understand lifestyle decision making behaviour, measure it with stated and revealed preference, model it with discrete choice and forecast it with agent based modelling.
These are the principles of lifestyle modelling which the paper develops in more detail putting the flesh on the bones developed during the recent ETC discussions. The innovation is in the development of the lifestyle ideas into a practical model architecture for discussion.
Association for European Transport