5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, March 2012 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 31/05/2012   
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APPENDIX 1 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 $35,170m and the calculated standard error in this case is $393m. The standard error is then used to interpret the level estimate of $35,170m.

For instance, the standard error of $393m indicates that:

  • There are approximately two chances in three that the real value falls within the range $34,777m to $35,563m (35,170m ± $393m)
  • There are approximately 19 chances in 20 that the real value falls within the range $34,384m to $35,956m (35,170m ± $786m)

The real 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 March Quarter 2012 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
38
65
75
Manufacturing
52
87
99
Electricity, Gas, Water and Waste Services
1
76
75
Construction
7
191
191
Wholesale Trade
62
56
82
Retail Trade
9
47
50
Transport, Postal and Warehousing
60
84
112
Information Media and Telecommunications
-
11
11
Financial and Insurance Services
8
21
24
Rental, Hiring and Real Estate Services
167
172
226
Professional, Scientific and Technical Services
80
72
112
Other Selected Services
67
90
114
Total
206
332
393
New South Wales
79
126
153
Victoria
82
93
120
Queensland
151
208
252
South Australia
4
77
78
Western Australia
102
150
196
Tasmania
12
32
37
Northern Territory
10
17
20
Australian Capital Territory
5
6
8
Australia
206
332
393
- 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 $40,012m and the next quarter the published level estimate is $35,170m.

In this example the calculated standard error for the movement estimate is $424m. The standard error is then used to interpret the published movement estimate of -$4,842m.

For instance, the standard error of $424m indicates that:
  • There are approximately two chances in three that the real movement over the two quarter period falls within the range -$5,266m to -$4,418m (-$4,842m ± $424m)
  • There are approximately nineteen chances in twenty that the real movement falls within the range -$5,672m to -$3,976m (-$4,824m ± $848m)

The following table shows the standard errors for March Quarter 2012 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
37
74
79
Manufacturing
45
133
148
Electricity, Gas, Water and Waste Services
6
23
18
Construction
8
217
217
Wholesale Trade
94
93
142
Retail Trade
11
60
63
Transport, Postal and Warehousing
48
137
149
Information Media and Telecommunications
1
11
11
Financial and Insurance Services
25
37
47
Rental, Hiring and Real Estate Services
136
179
217
Professional, Scientific and Technical Services
20
115
112
Other Selected Services
57
108
121
Total
191
380
424
New South Wales
142
188
246
Victoria
100
176
213
Queensland
41
242
244
South Australia
12
112
112
Western Australia
69
165
183
Tasmania
11
33
31
Northern Territory
13
12
18
Australian Capital Territory
2
9
9
Australia
191
380
424