What makes aeconomic model good or useful? Why does a model fail?

VVI dISCUSSION. Economic models From the IMF publication readings, "Economic Models: Simulations of Reality" in part 1, define economic model. What makes a model good or useful? Why does a model fail? Please respond to the discussion question. Then respond to at least one peer's post. All posts should be substantial - which means you are providing new information or insights. Substantial does NOT mean a lengthy post - in fact, posts should be concise and meaty for conversational purposes, not like a series of essays. Please include citations and references for information from outside sources, formatted in APA style