In this book, a baseline New Keynesian model is linearised around a possibly positive trend inflation rate. The trend inflation, i.e. target inflation rate, is brought about either by a forward-looking or contemporaneous Taylor rule. The model is based on the assumption of strategic complementarity in price-setting. Steady-state, determinacy and model dynamics are analysed. A focus is on different versions of trend-inflation dependent price-setting frequencies. Like in many other studies, welfare considerations do not justify an inflation target considerably above zero. It appears, however, that higher price-flexibility favours a slightly higher target. Overall, price-setting frequency is of considerable importance for the results.