[Handbook of Computational Economics] Volume 4 || Agent-Based Macroeconomics ✶ ✶The authors are grateful for helpful comments and suggestions from Tiziana Assenza, Jean-Philippe Bouchaud, Silvano Cincotti, Giovanni Dosi, Giorgio Fagiolo, Edoardo Gaffeo, Mauro Gallegati, Gavin Goy, Philipp Harting, Cars Hommes, Sander van der Hoog, Peter Howitt, Blake LeBaron, Marco Raberto, Andrea Roventini, Alberto Russo, and Isabelle Salle.