This study consists of four independent research papers covering different duopoly models. Chapter 1, 2 and 3 deal with bounded rational firms in a dynamic framework, whereas in chapter 4 a static model is considered. In chapter 1 the joint paper `Generalized adaptive expectations dynamics in two-stage games' with Herbert Dawid is introduced. The paper `Duopoly games with limited information sets' is presented in chapter 2. Chapter 3 deals with the joint paper with Seppo Orjasniemi. The title is `Quantity competition under local cost information'. Finally, the paper `A generalization of Boyer-Moreaux: On Stackelberg equilibria with differentiated products', which is a joint work with Nikolai M. Brandt, is presented in chapter 4.
