Income Inequality — Prelims Strategy

Prelims Strategy

Calculate mean and median independently. A change at the top affects the total and therefore the mean, while the middle observations may stay fixed. With an even number of ordered observations, average the two middle values rather than choosing the higher one as the median.

For the Gini, check scale and variable. A coefficient of 0.30 corresponds to an index of 30; neither is automatically a poverty percentage. A consumption Gini and a top income share cannot be compared through simple subtraction. Reference periods and survey or estimation methods also need to match before drawing a trend.

Use proportional scaling as a conceptual test. If each income doubles, shares remain the same, the standard Gini is unchanged and absolute gaps double. A person can nevertheless cross a fixed poverty line. Distinguish these outcomes rather than assuming that growth, poverty reduction and lower inequality must occur together. Select only the conclusion supported by the stated distribution and definitions.