Consumption Externalities, Heterogeneous Agents and Cycles

This paper studies the e¤ect of consumption externalities in a Ramsey model with heterogeneous agents and borrowing constraints. We consider two types of agents who di¤er in their initial wealth and discount factors. Further, we leave open the possibility of increase in consumption of one agent producing a positive (Keeping-Up with the Joneses) or a negative (Running-Away from the Joneses) effet over the marginal utility from own consumption of the other agent. We show that, at a steady-state equi- librium, inequality arises across agents which in turn implies that, agents have different consumption levels. Moreover, we show that, whenever the preferences display Keeping-Up with the Joneses feature, low elasticity of production factors substitution is no longer needed for the emergence of flip cycles and instability. Instead, only the external effects in consump- tion that plays a crucial role and promotes instability and the appearence of these endogeneous cycles.