We present conditions for the emergence of singularities in DGE models. We distinguish between slow-fast and impasse singularity types, review geometrical methods to deal with both types of singularity and apply them to DGE dynamics. We find that impasse singularities can generate new types of...

We present the first necessary and sufficient conditions for there to be a unique perfect-foresight solution to an otherwise linear dynamic model with occasionally binding constraints, given a fixed terminal condition. We derive further conditions on the existence of a solution in such models....

Since the beginnings of modern economics, economists sought to emulate the revolution in physics initiated by Newton’s ‘Principia’ (1687). Concepts from mechanics have influenced economic models both in terms of methodology and content. The aim of this theoretical paper is to put forward a...

Policy makers would like to prevent self-fulfilling fluctuations. Given the prevalence of occasionally binding constraints (OBCs) such as the zero lower bound (ZLB), this requires understanding the determinacy of models with OBCs. To this end, we derive existence and uniqueness conditions for...

This paper aims at providing macroeconomists with a detailed exposition of the New Keynesian DSGE model. Both the sticky price version and the sticky information variant are derived mathematically. Moreover, we simulate the models, also including lagged terms in the sticky price version, and...

We present the first necessary and sufficient conditions for there to be a unique perfect-foresight solution to an otherwise linear dynamic model with occasionally binding constraints, given a fixed terminal condition. We derive further conditions on the existence of a solution in such models....

Dynamic stochastic general equilibrium models with ex-post heterogeneity due to idiosyncratic risk have to be solved numerically. This is a nontrivial task as the cross-sectional distribution of endogenous variables becomes an element of the state space due to aggregate risk. Existing global...

This paper analyzes the sustainability of fiscal debt contingent on fiscal policy operating in two fiscal regimes. The first regime is characterized by active policy (not reacting to debt) and the other by passive fiscal policy (reacting to debt). The average duration for which either regime can...