This book consists of four essays on the fields of labour and health economics. All of them are concerned with the effects of behavioural and psychological factors. The first essay examines the effects of non-cognitive skills on tests scores, the second examines the effects of retirement on health outcomes, the third examines the effects of similarity between an unemployed person and his caseworker on employment outcomes, the fourth examines the effects of a caseworker's attitude towards cooperation with his client on employment outcomes. The latter two are joint work with Markus Frölich and Michael Lechner.