I've used visualizations like this "champagne glass" chart of income distribution by population quintile:
|Source: Sociological Images|
And this chart comparing Wall Street bonuses to the salaries of the average worker:
|Source: The Economist|
But the concept does not always sink in...
A colleague explained a "cookie sharing" exercise that she uses in her class, so I modified this demonstration for my own classroom using candy. (Individually-wrapped candy is cheaper to buy in bulk and is easier to distribute without a crumbly mess than cookies are.) To date, nothing has worked better to illustrate the unequal distribution of wealth than 100 pieces of candy...
EXPLAINING INEQUALITY: CANDY DISTRIBUTION EXERCISE
In a class of 20* students, I ask students to count off by 5.
With the champagne-glass income distribution chart on the screen, I call the 2s to the front of the room and hand out 12 pieces of individually-wrapped candy.
Each student walks away with 3 pieces.
Then I call the 3s, 4s, and 5s to the front of the room... Twelve students stand around while I count out 5 pieces of candy.
They complain. Occasionally one student dives in to snatch a chocolate before all of the pieces are taken. (Competition for scarce resources, perhaps?) I explain that they'll have to find a knife and divvy slivers of lollipop among the group.
I ask this group, the "lowest 60 percent"of the wealth distribution, to remain standing.
Then I call the 1s - the top quintile - to the front of the room. With some fanfare, I spread the remaining 82 pieces of candy across a desk.
The four students, if they choose to, can walk away with a hefty haul of 20 pieces each.
Usually students in the top quintile realize they do not each need 20+ pieces of candy. Occasionally a student will suggest that they can share their loot with the deprived 3s, 4s, and 5s. This can open up useful discussions of redistribution programs and of fairness in the distribution of resources.
Occasionally someone will suggest that, perhaps, the lowest 60 percent of the class did not work hard enough, and that, perhaps, the top 20 percent earned their diabetes-inducing haul of sweets. This can be an excellent opportunity to discuss how society defines inequality as fair. (I find that an effective response to the "fariness" issue is to pose the question "Do factory workers in China, who may work 10-14 hour workdays, 6 days a week, work less hard than we do?")
And because I'm trying to prove a data point, not start a riot in the classroom, I usually keep a spare stash of candy available to make sure, at the end of the lesson, that 3s, 4s, and 5s each get a piece of candy before they return to their seats.
*Note: This exercise works quite well in class of any size, but the number of pieces of candy should be adjusted accordingly... 200 pieces for a 40-student class, 50 pieces for a 10-student class, etc...