module 7 Flashcards
(46 cards)
what is economic growth
the growth rate of the real per capita GDP
what can GDP also be called a measure of
- average real per capita income
- since a way to measure GDP was by calculating total income
- so GDP is also a measure of total income
how do you determine who to put in which quintile
depends on the variable you want to compare the people by
what does the lowest quintile represent
20% of the population with the smallest values
what does the highest quintile represent
20% of the population with the highest values
if you had data of age and expenditure for each person, how do you construct the quintiles if they are based on the age variable
- sort the people by age (youngest to oldest)
- divide them into 5 equal groups
if you had data of age and expenditure for each person, how do you construct the quintiles if they are based on the expenditure variable
- sort the people by expenditure (least to most)
- divide them into 5 equal groups
what are deciles
- when you divide the population by 10 equal groups
- Ex. bottom income decile = 10% of the population with the lowest incomes
what are percentiles
- when you divide the population by 100 equal groups
- Ex. top percentile is the 1% of the population with the highest incomes
what is one way to analyze the income distribution
divide the population in quintiles based on income
how can you get a better picture of how total income is allocated in the population
- create a histogram of income
- if its skewed (especially to the right), then it means there is income inequality
why is looking at household income distribution still not perfect
because not all households are the same size
why would it be better to look at household income distribution than the distribution of income for each individual that is of working age
- some of the low income individuals are students that only work a few hours per year
- some are members of high income families who choose to be out of the labour force
- its better because it includes the income of all members of the household
what does it mean if the difference between the average and median is increasing
means that the allocation is becoming more unequal
what is the median
- the value that separates the population into 2 equal groups
- 50% of the population have incomes higher than the median, and 50% have incomes lower than the median
why are the averages higher than the medians (usually)
because many individuals have very high incomes compared with the average Canadians
what happens to the average and median if the income of the richest individuals increase
- the average increases
- the median remains unaffected
how do you plot the lorenz curve
- first need the share of total income by quintile
- then need the cumulative share of household income:
- Its the share of income of the 1st quintile (20% poorest), first 2 quintiles (40% poorest), first 3 (60% poorest), etc.
- Because of rounding errors, the last value doesn’t equal 100% (but around 100%)
- then plot the cumulative income share on the y axis and the cumulative households on the x axis
what is the gini coefficient
a measure based on the Lorenz curve
how do you calculate the gini coefficient
- the area between the perfect equality line and the Lorenz curve divided by the area below the equality line
- Since the perfect equality line has a slope of 1, the base (run) = 1 (100%), and the height (rise) = 1 (100%)
- The line makes a right angle triangle with the axes, so the area under the line is 0.5 (bh / 2 = (1)(1) / 2 = 0.5)
- So the Gini coefficient is x2 the area between the equality line and the Lorenz curve
how do you interpret the gini coefficient
- If the Lorenz curve = the equality line, the coefficient = 0
- higher coefficient = allocation is more unequal
is the gini coefficient a perfect measure of income inequality
- no
- can’t expect one number to provide a complete picture of income allocation
- Its a tool to compare inequalities, but doesn’t tell us everything about income distribution
can you compare inequality across countries with the gini coefficient
yes but it has to come from the same source
when is a household considered poor
if its income falls below the poverty line