Hausman (1978) developed a widely-used model specification test that has passed the test of time. The test is based on two estimators, one being consistent under the null hypothesis but inconsistent under the alternative, and the other being consistent under both the null and alternative...

This paper examines the impact of psychological needs on luxury consumption. Veblen's Theory of the Leisure Class (1899) invented the term "conspicuous consumption" to describe luxury goods and services, in which Veblen indicated the purpose of luxury consumption was to display wealth and social...