17Appendix A presents a model that abstracts from idiosyncratic income risk (essentially, setting σ2ψ = σ2θ = 0  ), and which produces results similar to those of our ‘realistic’ models. The simplification enables general equilibrium analysis at a small fraction of the computational cost. However, it is neither a recognizable representative agent model nor a respectable heterogeneous agents model, which may reduce its appeal to both audiences.