5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Jun 2010 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 26/08/2010   
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APPENDIX SAMPLING ERRORS


LEVEL ESTIMATES


INTRODUCTION

The estimates in this publication are based on a sample drawn from units in the surveyed population. Because the entire population is not surveyed, the published estimates are subject to sampling error. The most common way of quantifying such sampling error is to calculate the standard error for the published estimate or statistic.


EXAMPLE OF USE

The following example illustrates how to use the standard error to interpret a level estimate.

Let us say that the published level estimate for total capital expenditure is $27,735m and the calculated standard error in this case is $654m. The standard error is then used to interpret the level estimate of $27,735m.

For instance, the standard error of $654m indicates that:

  • There are approximately two chances in three that the correct value falls within the range $27,081m to $28,389m ($27,735m ± $654m)
  • There are approximately 19 chances in 20 that the correct value falls within the ranges $26,427m to $29,043m ($27,735m ± $1,308m)

The correct value in this case is the result we would obtain if we could enumerate the total population.

The following table shows the standard errors for June Quarter 2010 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
84
127
147
Manufacturing
13
171
173
Electricity, Gas, Water and Waste Services
111
25
111
Construction
11
254
254
Wholesale Trade
13
61
64
Retail Trade
18
79
79
Transport, Postal and Warehousing
48
96
110
Information Media and Telecommunications
-
34
34
Financial and Insurance Services
2
21
21
Rental, Hiring and Real Estate Services
292
403
522
Professional, Scientific and Technical Services
92
89
128
Other Selected Services
109
100
152
Total
369
529
654
New South Wales
164
278
354
Victoria
174
387
405
Queensland
190
247
344
South Australia
113
88
135
Western Australia
75
163
172
Tasmania
4
18
20
Northern Territory
6
41
42
Australian Capital Territory
1
7
7
Australia
369
529
654
- nil or rounded to zero (including null cells)



MOVEMENT ESTIMATES


EXAMPLE OF USE

The following example illustrates how to use the standard error to interpret a movement estimate.

Let us say that one quarter the published level estimate for total capital expenditure is $23,837m and the next quarter the published level estimate is $27,735m. In this example the calculated standard error for the movement estimate is $652m. The standard error is then used to interpret the published movement estimate of $3,898m.

For instance, the standard error of $652m indicates that:
  • There are approximately two chances in three that the correct movement over the two quarter period falls within the range $3,246m to $4,550m ($3,898m ±$652m)
  • There are approximately nineteen chances in twenty that the correct movement falls within the range $2,594m to $5,202m ($3,898m ± $1,304m).

The following table shows the standard errors for June Quarter 2010 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
48
134
142
Manufacturing
29
164
167
Electricity, Gas, Water and Waste Services
33
24
41
Construction
10
274
274
Wholesale Trade
13
127
129
Retail Trade
30
107
118
Transport, Postal and Warehousing
30
135
145
Information Media and Telecommunications
7
21
22
Financial and Insurance Services
13
79
80
Rental, Hiring and Real Estate Services
336
265
425
Professional, Scientific and Technical Services
35
100
105
Other Selected Services
55
115
126
Total
353
513
652
New South Wales
95
310
330
Victoria
310
245
408
Queensland
73
305
312
South Australia
12
103
107
Western Australia
73
178
192
Tasmania
6
20
21
Northern Territory
8
48
51
Australian Capital Territory
5
7
9
Australia
353
513
652