This thesis contributes to the existing literature on personality traits and economic preference parameters by analyzing the stability of some of the main traits and parameters. Specically, I investigate whether (1) they change as individuals age in the cross-section and by individual, and (2) whether they are affected by an individual's personal situation changes. I use data from a large Dutch household panel survey (DHS) that includes measures for two key economic preference parameters: Risk Aversion and Future Orientation. On personality traits, the dataset contains information on the “Big Five”, a set of five general traits (Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism) that are said to capture individual differences in personality, and Economic Locus of Control, a lower-level (i.e. more specic; narrower) trait that measures the extent to which an individual believes economic outcomes are a result of her own actions. My results using pooled cross-section analysis suggest that most preference parameters and personality traits are not stable over time and are changed by many of the events investigated; in particular, there is strong evidence that Big Five Openness is negatively affected by marriage and widowing. Using fixed effects and random effects methodologies on a sub-sample of the data, most of the changes attributed to the events are no longer signifficant but the coefficients of marriage and widowing on Openness remain signifcant of similar size. If personality is modeled as a unit root process and their differences over four years are regressed against event dummies and age group indicators, the effects that are statistically signiffcant reduce to only a few, and the evidence on age instability is also contested. Overall, the evidence suggest that the hypothesis of age stability for most personality traits can be rejected (with the exception of Locus of Control) and only Openness seems to be negatively affected by marriage and widowing.