Interventions aimed to change behavior (so called nudges) are becoming more and more popular among policymakers. However, in order to be able to effectively use nudges, it is important to understand when and why people find them acceptable. The objective of this thesis is therefore to improve the understanding of when nudges are judged to be acceptable. The thesis focuses on a model for behavioral change. The model contains two parts, nudge technique and acceptance of nudges. Nudge technique refers to how the nudge is designed to function in regard to psychological mechanism and functionality. The nudge technique part of the model is expanded and problematized from an ethical perspective in the first part of this thesis, by exemplifying psy...