Generating life course trajectory sequences with recurrent neural networks and application to early detection of social disadvantage

Using long-running panel data from the Household, Income and Labour Dynamics in Australia (HILDA) survey collected annually between 2001 and 2015, we aim to generate a sequence of events for individuals by processing real life trajectories one step at a time and predict what comes next. This is motivated by the need for understanding and predicting forthcoming patterns from these disadvantage dynamics which are represented by multiple life-course trajectories evolutions over time. In this paper, given longitudinal trajectories created from HILDA survey waves, we develop a model with Long Short-term Memory recurrent neural networks to generate complex trajectory sequences with long-range structure. Our method uses a multi-layered Long Short-Term Memory (LSTM) approach to map the input sequence to a vector of a fixed dimensionality, and then another deep LSTM to decode the target sequence from the vector. The generated sequences over time use the social exclusion monitor (SEM) indicator to determine the level of social disadvantage for each individual. The sequences are encoded by predefined social exclusion factors, which are binary values to indicate the occurrence of corresponding factors. To model the correlations among social exclusion domains, we use the Mixture Density Networks which are parameterized by the outputs of LSTM. Our main result is the high prediction accuracy on personal life course trajectories created from real HILDA data. Moreover, the proposed model can synthesize, and impute some missing trajectories given partial observations from respondent individuals. More importantly, we examine the relative roles of different advantage dimensions in explaining changes in life trajectories in Australia, and find that the domains of employment, education, community and personal safety are highly correlated to the decreased disadvantage measurement. While, domains regarding material resources, health and social support are of direct relevance to increase social disadvantage with varied contribution extent.