AP Microeconomics Quiz: Inequality

What this quiz covers

This quiz focuses on Inequality, giving you a quick way to practice the rules, question types, and explanations that matter most for AP Microeconomics.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. inherited wealth as the sole determinant of an individual's lifetime economic success.
2. a progressive tax system that has successfully eliminated all income inequality.
3. a combination of an individual's human capital and their access to social capital. (correct answer)
4. the complete elimination of labor market discrimination in all sectors of the economy.

Explanation: This scenario highlights two key sources of economic advancement. The degree in a high-demand field represents an increase in the individual's human capital (skills and knowledge). The professional network from the university represents social capital (valuable connections). Both contributed to the successful outcome.

Question 2

1. A progressive income tax where higher earners pay a larger percentage of their income in taxes.
2. A proportional tax where all individuals pay the same percentage of their income in taxes.
3. A regressive payroll tax that applies only to the first $100,000 of earned income. (correct answer)
4. An estate tax levied on large inheritances passed between generations.

Explanation: A regressive tax takes a larger percentage of income from low-income earners than from high-income earners. A payroll tax with an income cap is regressive because earnings above the cap are not taxed, meaning high-income individuals pay a smaller fraction of their total income in this tax. This increases after-tax inequality.

Question 3

1. Economy A shows greater inequality because the bottom 40% receives a smaller share of income.
2. Economy B shows greater inequality because the top 20% receives a larger share of income. (correct answer)
3. Economy A shows greater inequality because the top 20% receives a smaller share of income.
4. Economy B shows greater inequality because its total income is higher.
5. Economy A shows greater inequality because equal shares across quintiles would indicate inequality.

Explanation: This question tests your ability to interpret income inequality from quintile data. The Lorenz curve plots cumulative income share against cumulative population share, with the 45-degree line representing perfect equality. Looking at the data, Economy B shows the bottom 20% receiving only 3% of income (vs 6% in A) and the top 20% receiving 53% (vs 42% in A). This represents a more unequal distribution because income is more concentrated at the top. A common misconception is thinking that higher total income means greater inequality, but inequality measures distribution, not absolute amounts. To assess inequality, compare how far each distribution deviates from equal shares (20% each) - the greater the deviation, especially concentration at the top, the greater the inequality.

Question 4

1. Inequality increased because the top 20% receives a smaller share of income.
2. Inequality decreased because the bottom 60% receives a larger combined share of income. (correct answer)
3. Inequality increased because the bottom 20% receives a larger share of income.
4. Inequality decreased because total income must have fallen.
5. Inequality increased because equal quintile shares would indicate inequality.

Explanation: This question tests interpretation of changing income inequality over time. The Lorenz curve visualizes income distribution, with movement toward the equality line indicating reduced inequality. Comparing the distributions, the bottom three quintiles increased their shares (4% to 5%, 9% to 10%, 14% to 15%) while the top quintile decreased from 50% to 47%. This redistribution from the top to lower quintiles represents decreased inequality. A common misconception is thinking that any increase in lower quintile shares means increased inequality. The key insight is that when income shifts from higher to lower quintiles, making the distribution more equal, inequality decreases - exactly what occurred with this policy change.

Question 5

1. Metro Area R shows greater inequality because the bottom 20% receives a smaller share of income. (correct answer)
2. Metro Area S shows greater inequality because the top 20% receives a smaller share of income.
3. Metro Area S shows greater inequality because the bottom 40% receives a larger combined share of income.
4. Metro Area R shows greater inequality because its average income is higher.
5. Metro Area S shows greater inequality because equal quintile shares would indicate inequality.

Explanation: This question tests interpretation of income inequality from quintile distributions. The Lorenz curve illustrates how income is distributed, with greater deviation from equality indicating higher inequality. Metro Area R shows the bottom 20% receiving only 3% of income compared to 6% in Area S, while both areas have similar top quintile shares (50% vs 45%). The key difference is the more severe deprivation at the bottom in Area R, indicating greater inequality. A common misconception is focusing only on the top quintile, but inequality reflects the entire distribution. When comparing areas, examine both extremes - Area R's combination of very low bottom share (3%) and high top share (50%) represents greater inequality than Area S's more moderate distribution.

Question 6

1. Country Y shows greater inequality because the bottom 20% receives a larger share of income.
2. Country X shows greater inequality because the top 20% receives a larger share of income. (correct answer)
3. Country Y shows greater inequality because the top 20% receives a smaller share of income.
4. Country X shows greater inequality because its average income level is higher.
5. Country Y shows greater inequality because equal quintile shares would indicate inequality.

Explanation: This question requires interpreting income inequality from quintile distributions. The Lorenz curve visualizes income distribution, where deviation from the equality line indicates inequality. Examining the data, Country X's top 20% receives 50% of income while Country Y's top 20% receives 42%, indicating greater concentration of income at the top in Country X. Additionally, Country X's bottom 20% receives only 5% compared to Y's 8%, showing more severe deprivation at the bottom. A key misconception is that higher average income indicates greater inequality - inequality measures distribution patterns, not income levels. When comparing distributions, focus on the concentration of income: Country X shows greater inequality with its 50% top quintile share versus Y's 42%.

Question 7

1. the country's Lorenz curve is a straight 45-degree line.
2. the marginal productivity theory of income distribution fully explains all income differences.
3. factors such as discrimination, and unequal access to human and social capital may be present. (correct answer)
4. the country must have a regressive tax system as its primary source of government revenue.

Explanation: While productivity differences explain some income variation, persistent and significant gaps between demographic groups (defined by race, gender, etc.) often point to systemic issues. These can include historical and ongoing discrimination in labor and housing markets, as well as unequal access to quality education (human capital) and influential networks (social capital).

Question 8

1. Inequality is higher in Region 2 because the top 20% receives a larger share of income.
2. Inequality is lower in Region 2 because the bottom 40% receives a smaller share of income.
3. Inequality is unchanged because each quintile's income share is the same in both regions. (correct answer)
4. Inequality is higher in Region 2 because total income must have increased.
5. Inequality is higher in Region 1 because equal shares across quintiles would indicate inequality.

Explanation: This question tests understanding of income inequality interpretation when distributions are identical. The Lorenz curve represents cumulative income distribution, with the equality line showing perfectly equal distribution. Examining both regions' data reveals identical quintile shares: 4%, 9%, 14%, 23%, and 50% respectively. Since the income shares are exactly the same, the inequality level is unchanged between regions. A common error is assuming that identical distributions in different regions must show different inequality due to potential differences in total income. Remember that inequality measures the relative distribution of income, not absolute amounts - when quintile shares are identical, inequality is identical regardless of the regions' total incomes.

Question 9

1. Region X, because its Lorenz curve lies closer to the line of equality than Region Y
2. Region Y, because its Lorenz curve lies closer to the line of equality than Region X
3. Region Y, because its Lorenz curve lies farther from the line of equality than Region X (correct answer)
4. Region X, because a curve farther from the line of equality indicates less inequality
5. Region X, because the graph does not provide information about inequality without average income data

Explanation: Interpreting income inequality is the skill here, using Lorenz curves. The Lorenz curve plots the cumulative percentage of income received by the cumulative percentage of households from lowest to highest income, and the line of equality is the 45-degree line representing perfect income equality. The graph shows Lorenz curves for Region X and Region Y. Region Y shows greater income inequality because its Lorenz curve lies farther from the line of equality than Region X's, indicating more income concentration. A common misconception is that a curve farther from equality reflects higher average income, but it actually measures distributional inequality, independent of total income. A transferable strategy is to observe the extent of the bow in the Lorenz curve. The greater the bow away from the equality line, the greater the income inequality.

Question 10

1. Income is perfectly equally distributed, because the Lorenz curve coincides with the line of equality
2. Income is more unequally distributed, because the Lorenz curve lies below the line of equality (correct answer)
3. Income is more unequally distributed, because the Lorenz curve lies above the line of equality
4. Income is more equally distributed, because the Lorenz curve lies farther from the line of equality
5. Income is higher on average, because the Lorenz curve reaches 100% at 100% of households

Explanation: Interpreting income inequality is the skill here, using Lorenz curves. The Lorenz curve plots the cumulative percentage of income received by the cumulative percentage of households from lowest to highest income, and the line of equality is the 45-degree line representing perfect income equality. The graph shows the Lorenz curve for Country Z. The curve indicates more unequal income distribution because it lies below the line of equality, showing that lower-income households receive less than their proportional share. A common misconception is that a curve below the equality line means lower average income, but it reflects distributional inequality, not total income. A transferable strategy is to observe the position relative to the equality line. The greater the bow away from the equality line, the greater the income inequality.

Question 11

1. The Lorenz curve would shift closer to the line of perfect equality, and the Gini coefficient would increase.
2. The Lorenz curve would shift further from the line of perfect equality, and the Gini coefficient would increase.
3. The Lorenz curve would shift closer to the line of perfect equality, and the Gini coefficient would decrease. (correct answer)
4. The Lorenz curve would shift further from the line of perfect equality, and the Gini coefficient would decrease.

Explanation: A progressive tax system combined with transfer payments to the poor redistributes income from higher earners to lower earners. This makes the income distribution more equal, which is represented by the Lorenz curve shifting closer to the 45-degree line of perfect equality and a corresponding decrease in the Gini coefficient.

Question 12

1. the maximum possible Gini coefficient of 1.0, indicating complete concentration of income.
2. a situation of perfect income equality, where each percentage of the population earns the same percentage of the total income. (correct answer)
3. a situation of perfect income inequality, where one household earns all of the national income.
4. the typical income distribution found in a developed market economy after taxes and transfers.

Explanation: The 45-degree line, often called the line of perfect equality, shows a direct one-to-one relationship. For example, it indicates that the bottom 20% of households earn 20% of the income, the bottom 50% earn 50%, and so on. The further the actual Lorenz curve bows away from this line, the greater the inequality.

Question 13

1. the social and political power held by the group to which the individual belongs.
2. the contribution their last unit of labor adds to their employer's total revenue. (correct answer)
3. the level of taxation imposed by the government on different income brackets.
4. the amount of wealth they inherited from their parents or other relatives.

Explanation: The marginal productivity theory of income distribution posits that each factor of production, including labor, is paid a price equal to its marginal revenue product (MRP). MRP is the additional revenue generated by employing one more unit of that factor. Therefore, an individual's income is linked to their productivity and the value of the output they help create.

Question 14

1. Inequality increased, because the Lorenz curve in Year 5 is closer to the line of equality
2. Inequality decreased, because the Lorenz curve in Year 5 is closer to the line of equality
3. Inequality increased, because the Lorenz curve in Year 5 is farther from the line of equality (correct answer)
4. Inequality did not change, because both Lorenz curves intersect at 0% and 100%
5. Inequality decreased, because the Lorenz curve in Year 5 implies higher average income

Explanation: Interpreting income inequality is the skill here, using Lorenz curves. The Lorenz curve plots the cumulative percentage of income received by the cumulative percentage of households from lowest to highest income, and the line of equality is the 45-degree line representing perfect income equality. The graph shows Lorenz curves for Metro A in Year 1 and Year 5. Inequality increased because the Lorenz curve in Year 5 is farther from the line of equality, indicating growing income concentration. A common misconception is that a farther curve reflects increased average income, but it shows heightened inequality in distribution, independent of total income. A transferable strategy is to compare curve positions relative to the equality line over time. The greater the bow from the equality line, the greater the income inequality.

Question 15

1. Country P, because its Lorenz curve is closer to the line of equality than Country Q
2. Country Q, because its Lorenz curve is closer to the line of equality than Country P
3. Country P, because a Lorenz curve farther from the line of equality indicates less inequality
4. Country Q, because its Lorenz curve is farther from the line of equality than Country P (correct answer)
5. Country P, because the Lorenz curve indicates higher average income when it bows outward

Explanation: Interpreting income inequality is the skill here, using Lorenz curves. The Lorenz curve plots the cumulative percentage of income received by the cumulative percentage of households from lowest to highest income, and the line of equality is the 45-degree line representing perfect income equality. The graph shows Lorenz curves for Country P and Country Q. Country Q shows greater inequality because its Lorenz curve is farther from the line of equality than Country P's, reflecting more uneven distribution. A common misconception is that a farther curve indicates higher average income, but it measures greater inequality in shares, not total income. A transferable strategy is to evaluate the degree of bowing in the curve. The greater the bow from the equality line, the greater the income inequality.

Question 16

1. Inequality decreased, because the Lorenz curve after the change is closer to the line of equality (correct answer)
2. Inequality increased, because the Lorenz curve after the change is closer to the line of equality
3. Inequality decreased, because the Lorenz curve after the change is farther from the line of equality
4. Inequality increased, because the economy's total income must have grown after the change
5. Inequality did not change, because both curves end at 100% income at 100% of households

Explanation: Interpreting income inequality is the skill here, using Lorenz curves. The Lorenz curve plots the cumulative percentage of income received by the cumulative percentage of households from lowest to highest income, and the line of equality is the 45-degree line representing perfect income equality. The graph shows Lorenz curves for Economy 1 before and after the tax-and-transfer change. Inequality decreased because the Lorenz curve after the change is closer to the line of equality, indicating a more even income distribution. A common misconception is that a curve closer to equality means reduced total income, but it shows improved equality in distribution, regardless of total income. A transferable strategy is to compare the proximity to the equality line over time. The smaller the bow from the equality line, the lesser the income inequality.

Question 17

1. Inequality decreased because the top 20% receives a larger share of income.
2. Inequality increased because the top 20% receives a larger share of income. (correct answer)
3. Inequality decreased because the bottom 40% receives a smaller combined share of income.
4. Inequality increased because total income must have risen.
5. Inequality decreased because equal quintile shares would indicate inequality.

Explanation: This question tests understanding of how income inequality changes over time. The Lorenz curve represents income distribution, where movement away from the equality line indicates increased inequality. Comparing the years, the top 20% increased their share from 42% to 46%, while the bottom 20% decreased from 6% to 4% and the second quintile from 12% to 10%. This represents increased concentration of income at the top and reduced shares for lower quintiles. A common error is thinking that higher top quintile shares mean decreased inequality. Remember that when income becomes more concentrated at the top while lower quintiles lose share, inequality increases - the distribution moves further from the equal 20% benchmark for each quintile.

Question 18

1. Province M shows greater inequality because the bottom 20% receives a larger share of income.
2. Province N shows greater inequality because the top 20% receives a larger share of income. (correct answer)
3. Province M shows greater inequality because the top 20% receives a smaller share of income.
4. Province N shows greater inequality because its average income is higher.
5. Province M shows greater inequality because equal quintile shares would indicate inequality.

Explanation: This question requires comparing income inequality between two provinces using quintile data. The Lorenz curve plots cumulative income shares, with greater deviation from the equality line indicating higher inequality. Province N shows extreme inequality with the top 20% receiving 60% of income (versus 30% in M) and the bottom 20% receiving only 2% (versus 10% in M). This represents a highly unequal distribution with severe concentration at the top. Students often mistakenly think that a larger bottom quintile share indicates greater inequality, but the opposite is true. To assess inequality, examine how concentrated income is at the extremes - Province N's 60% top share versus M's 30% clearly shows N has much greater inequality.

Question 19

1. Economy C shows greater inequality because the top 20% receives a smaller share of income.
2. Economy D shows greater inequality because the top 20% receives a larger share of income. (correct answer)
3. Economy C shows greater inequality because the bottom 20% receives a larger share of income.
4. Economy D shows greater inequality because its total income is higher.
5. Economy C shows greater inequality because equal shares across quintiles would indicate inequality.

Explanation: This question assesses interpretation of income inequality from quintile data. The Lorenz curve illustrates income distribution, where greater deviation from the equality line indicates higher inequality. Economy D shows extreme concentration with the top 20% receiving 55% of income (versus 38% in C) and the bottom 20% receiving only 2% (versus 7% in C). This represents significantly greater inequality as income is heavily concentrated at the top while the bottom quintiles receive minimal shares. Students often confuse higher total income with greater inequality, but inequality measures distribution patterns, not income levels. To evaluate inequality, examine the deviation from equal 20% shares - Economy D's 55% top share and 2% bottom share show much greater inequality than Economy C's more moderate distribution.

Question 20

1. Inequality decreased because the top 20% receives a larger share of income.
2. Inequality increased because the bottom 40% receives a larger combined share of income.
3. Inequality increased because the top 20% receives a larger share of income. (correct answer)
4. Inequality decreased because total income must have increased.
5. Inequality decreased because equal quintile shares would indicate inequality.

Explanation: This question requires analyzing changes in income inequality between two time periods. The Lorenz curve visualizes income distribution, where movement away from the equality line indicates increased inequality. Comparing the years, the top 20% increased their share from 36% to 40%, while lower quintiles saw decreases (bottom from 9% to 7%, second from 14% to 12%). This represents increased concentration of income at the top and reduced shares for lower-income groups. Students sometimes confuse larger bottom quintile shares with increased inequality, but the opposite is true. The key insight is that when income shifts from lower to higher quintiles, making the distribution less equal, inequality increases - exactly what happened from Year A to Year B.