Each of us leaves many digital traces. For example, when we buy things in supermarkets and use loyalty cards to get benefits the supermarket records our purchases, creating a representation of our habits and preferences. Companies have been using aggregates of these data to track sales of their products, and to understand aspects of context that can impact sales levels, and to target marketing and promotions. But can these data be utilized for higher public impact helping individuals, economies and society at large? For example, can we learn about causes and consequences of mental health illnesses and routes to wellbeing through objectively tracked real world behaviours and choices? Up to now longitudinal cohort studies – like ALSPAC – allowed to use rich genetic, biomedical and early environment data to explain real world outcomes such as mental health illnesses and wellbeing. However, these outcomes often are self-reported which makes it challenging to unpick relationships in the data. This project aims to link objective measures of behaviour traced through retail and banking data to provide a set of variables reflecting objectively measured real world behaviours and decisions. These can be then linked to rich genetic, bio-medical and early environment data already collected on longitudinal cohorts and allow to investigate causes and consequences of real world outcomes such as mental health issues and wellbeing.