of consumption with respect to income). "Significant" In common usage, "significant" usually means "noteworthy" or "of substantial importance". In econometrics—the use of statistical techniques in economics—"significant" means "unlikely to have occurred by chance". For example, suppose one wishes to find if the minimum wage rate affects firms' decisions on how much labor to hire. If the data show, on the basis of statistical techniques, an effect of a particular non-zero magnitude, one wants to know whether that non-zero magnitude could have arisen in the data by chance when in fact the true effect is zero. If a statistical test shows that there is less than, say, a 5% chance that one would have found this particular value if the true value were zero, then it is said that the estimate is "significant at the 5% level". If not, then it is said that the estimate is "insignificant at the 5% level". Note, however, that the less precise phrase "economically significant" is sometimes used by economists to mean something very similar to the common usage of "significant". If the effect of the minimum wage on hiring decisions were found to be very small and yet the numerical result is very unlikely to have occurred only by chance, then the estimated effect is said to be statistically significant but not significant economically. "Biased" In common usage "biased" generally means "prejudiced". In econometrics, the estimate of the effect of one thing on another (say, the estimate of the effect of the minimum wage upon employment decisions) is said to be "biased" if the technique that was used to obtain the estimate has the effect that, a priori, the expected value of the estimated effect differs from the true effect, whatever the latter may be. In this case the technique, as well as the estimate obtained with the technique, is called "biased". Researchers are likely to view a biased estimate with suspicion. "Dummy" In common usage, dummy can offensively refer to someone who is silent or unintelligent, or to a mannequin or puppet. In econometrics, dummy generally refers to a binary variable that indicates whether a certain quality is present or absent. So, for example, a "male dummy" would refer to a variable indicating that someone is male, rather than referring to an unintelligent male or a male puppet. "Elasticity" In general usage elasticity refers to flexibility. In economics it refers to a quantitative