What are the differences between the condensed and the unabridged versions of Distribution of Lives?
For this please go to the book and ebook page.
I see many reference to the MAJ. What is it?
A quick response:
The MAJ refers to the bottom 60% of the population. The MAJ number refers to the percentage income share that they received. It is the latter form (the number) which usually is of primary interest when discussing income distribution.
The detailed response:
The MAJ is the percentage share of income that bottom the 60% majority of the population receives. It derives its name from: MAJority.
With an equitable income distribution, the 60% majority receives about 33% or more of total income earned. With an inequitable, grossly-unfair distribution, the 60% majority receives about 25% or less of the income. These two conditions respectively would be referred to as a MAJ33 and MAJ25.
In the same fashion the MAJ can be used to describe the percentage share of Wealth that is received. But this a more complicated topic because the WealthMAJ is far lower than the IncomeMAJ. That matter is covered in the book.
The MAJ is an intuitively friendly way of understanding income and wealth distributions.
In the field, there is a technical number called the Gini. The Gini is difficult to understand. Even once understood, it thwarts productive analysis. The MAJ is a useful replacement. It appears along with the Gini in the spreadsheets. You may elect to use whichever you prefer.
I see many references to the X$. What is it?
You probably have heard people saying, for example, that a certain CEO makes an income 200 times the average income. This is the X$ -- explicitly a 200X$. Similarly all incomes from the lowest to the highest can be described in X$s. They indicate the fractional share of the average income that each person earns. When a person receives less than the average income the X$ is less than one, for example, 0.75. When a person receives more than the average, say three times more, that person has a the 3X$ income.
These X$ curves serve to exactly describe the distribution from bottom to top. For example the general case of X$ curves for central tendencies for all distributions are substantially contained in the lookup-table spreadsheet.
On the other hand you can look at the historical record using Jeanes' methods to describe the X$ curves based on Congressional Budget Office data.
Understanding the general lookup table cases and the explicit historical cases are equally important.
In all instances the X$ can be multiplied times the average earnings to get an income stated in currency for any nation in the world. For example, in the instances that we have mentioned of a 0.75X$ and a 3X$, each of these would respectively convert to $30,000 and $144,000 when multiplied times the average income of $48,000. So whether the national average per capita income is high or low and regardless of what currency is used, multiplying the average by the X$ curve for the prevailing distribution gives a good estimate of incomes for every person, from the bottom to the top incomes throughout the nation.