Half the employee population share 10% of the total wage

Singapore Has The Highest Income Inequality Compared to the OECD Countries | The Heart Truths (Feb 2013)
The above blog uses the Singapore government statistics on Gini coefficient calculated on per household member income, which works out to 0.478 for 2012.

But at the average household member level, many sharp distinctions get ironed off. For example, a man earning $20,000, with a five-member household, will show an income of $4,000 per household member. Another single man earning $4,000 living alone will show the same income per household member.

How does the Gini coefficient look like if we consider individual employee wages?
From the calculations below, we see a very unequal picture.

1. About half the employees share only 10% of the total wages.
2. Three quarters of the employees share one quarter of the total wages.
3. The bottom 20% make only 2% of the total wages. 
4. The top 20% make 70% of the total wages. 
5. The Gini coefficient based on the wage table is estimated at 0.57.

Suppose the top 20% has this yummy strawberry pie for each person.

from scienceblog.com

The bottom 20% will have to share this pie among 35 persons. Less than a strawberry each.

Calculations

Monthly wage 2011	Number	Estimated Wage	Number* est. wage *12mth ($million)	%employee	%total wages
TOTAL	1,735,422		136,920
Below   $400	79,916	400	383.6	4.60	0.28
$  400   –   $  799	105,917	600	762.6	6.10	0.56
$  800   –   $  999	108,531	850	1107.0	6.25	0.81
$1,000  –  $1,499	164,253	1250	2463.8	9.46	1.80
$1,500  –  $1,999	177,511	1750	3727.7	10.23	2.72
$2,000  –  $2,999	333,420	2500	10002.6	19.21	7.31
$3,000  –  $4,499	328,079	3750	14763.6	18.90	10.78
$4,500  –  $4,999	65,597	4750	3739.0	3.78	2.73
subtotal of above	1,363,224		36949.9	78.55	26.99
$5,000  and  Above	371,870	22402	99970.1	21.43	73.01

Sources:
CPF report of employee wages
Asiaone Mar 2013: wage share of GDP is about 42%
GDP for 2011 is $326 billion. Total wages estimated at 42% of GDP= $136.9 billion.
Estimated wage is the middle of the range in column 1. For the last row, it is the remainder amount from total wages.

The cumulative percentages are below.

Monthly wage 2011	Cumulative	Cumulative
TOTAL	%employee	%total wage
Below   $400	4.60	0.28
$  400   –   $  799	10.71	0.84
$  800   –   $  999	16.96	1.65
$1,000  –  $1,499	26.43	3.45
$1,500  –  $1,999	36.66	6.17
$2,000  –  $2,999	55.87	13.47
$3,000  –  $4,499	74.77	24.26
$4,500  –  $4,999	78.55	26.99
$5,000  and  Above	100	100

In groups of 20%, the rounded numbers are:

%employee	%wage
20	2
40	7
60	16
80	27
100	100.00

These are based only on wages. Other incomes such as dividend, savings interest and rental income are not included.