Academic economists have written profusely about the issue of inequality as it has become more pronounced since the early 1980s. However, they have been totally ineffective in changing the trajectory from one that favors the rich and powerful to one that has a fairer distribution of economic product.
This graphic shows how wealth has increased substantially through life when it is the mean (average) that is used to make the plot. On the other hand when the median, that is the middle value of the dataset, the progress is inconsequential.
When talking about average, it is important to distinguish between mode, median, and mean. The mean is the average of a data set. The mode is the most common number in a data set. The median is the middle of the set of numbers. In common use average normally is the mean, but as the above graphic shows, there is a very big difference between the mean and the median.