Distal affiliative cues like smiles and gestures serve as incentive stumuli; they motivate approach-related tendencies served by the release

Which statement is a good description of a model? a) models are a description of nature based only on one or two variables. b) models are testable ideas but they are not very to most people. c) models are a description of nature that predicts more accurately than real events. d) models are an approximiation of a real system that omits all but most essential variables in a system.

People are willing to pay more for a diamond than for a bottle of water because

Which area of economics uses value judgments to make recommendations for future actions?