5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Sep 2018  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 29/11/2018   
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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 $29,268m and the calculated standard error in this case is $370m. The standard error is then used to interpret the level estimate of $29,268m.

For instance, the standard error of $370m indicates that:

  • There are approximately two chances in three that the real value falls within the range $28,898m to $29,638m ($29,268m ± $370m)
  • There are approximately 19 chances in 20 that the real value falls within the range $28,528m to $30,008m ($29,268m ± $740m)

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 September quarter 2018 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
69
42
95
Manufacturing
42
93
110
Electricity, Gas, Water and Waste Services
29
39
50
Construction
21
172
170
Wholesale Trade
15
69
74
Retail Trade
72
52
100
Transport, Postal and Warehousing
22
153
155
Information Media and Telecommunications
2
33
34
Financial and Insurance Services
28
40
51
Rental, Hiring and Real Estate Services
86
140
149
Professional, Scientific and Technical Services
66
82
104
Other Selected Services
109
109
166
Total
188
328
370
New South Wales
82
203
228
Victoria
88
161
186
Queensland
65
142
162
South Australia
89
74
116
Western Australia
79
117
147
Tasmania
30
31
45
Northern Territory
32
12
32
Australian Capital Territory
6
18
19
Australia
188
328
370


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 $31,945m and the next quarter the published level estimate is $29,268m.

In this example, the calculated standard error for the movement estimate is $442m. The standard error is then used to interpret the published movement estimate of $2,677m.

For instance, the standard error of $442m indicates that:
  • There are approximately two chances in three that the real movement over the two-quarter period falls within the range $2,235m to $3,119m ($2,677m ± $442m).
  • There are approximately 19 chances in 20 that the real movement falls within the range $1,793m to $3,561m ($2,677m ± $884m).

The following table shows the standard errors for September quarter 2018 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
59
52
96
Manufacturing
56
96
112
Electricity, Gas, Water and Waste Services
31
57
68
Construction
14
225
227
Wholesale Trade
21
114
120
Retail Trade
121
86
134
Transport, Postal and Warehousing
31
170
177
Information Media and Telecommunications
2
42
42
Financial and Insurance Services
38
54
65
Rental, Hiring and Real Estate Services
134
81
156
Professional, Scientific and Technical Services
58
103
111
Other Selected Services
147
151
198
Total
271
327
442
New South Wales
188
250
333
Victoria
113
172
190
Queensland
119
195
231
South Australia
92
129
157
Western Australia
71
116
139
Tasmania
34
67
78
Northern Territory
15
14
21
Australian Capital Territory
8
30
33
Australia
271
327
442