5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Dec 2018  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 28/02/2019   
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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 $33,769m and the calculated standard error in this case is $460m. The standard error is then used to interpret the level estimate of $33,769m.

For instance, the standard error of $460m indicates that:

  • There are approximately two chances in three that the real value falls within the range $33,309m to $34,229m ($33,769m ± $460m)
  • There are approximately 19 chances in 20 that the real value falls within the range $32,849m to $34,689m ($33,769m ± $920m)

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 December quarter 2018 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
74
38
93
Manufacturing
57
122
140
Electricity, Gas, Water and Waste Services
66
20
67
Construction
17
203
205
Wholesale Trade
18
82
86
Retail Trade
91
78
142
Transport, Postal and Warehousing
78
123
142
Information Media and Telecommunications
204
56
220
Financial and Insurance Services
85
53
110
Rental, Hiring and Real Estate Services
111
156
193
Professional, Scientific and Technical Services
36
74
91
Other Selected Services
99
124
166
Total
339
340
460
New South Wales
132
185
223
Victoria
128
182
232
Queensland
116
186
220
South Australia
93
60
112
Western Australia
57
149
162
Tasmania
15
40
44
Northern Territory
24
25
37
Australian Capital Territory
4
9
9
Australia
339
340
460


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 $29,440m and the next quarter the published level estimate is $33,769m.

In this example, the calculated standard error for the movement estimate is $435m. The standard error is then used to interpret the published movement estimate of $4,329m.

For instance, the standard error of $435m indicates that:
  • There are approximately two chances in three that the real movement over the two-quarter period falls within the range $3,894m to $4,764m ($4,329m ± $435m).
  • There are approximately 19 chances in 20 that the real movement falls within the range $3,459m to $5,199m ($4,329m ± $870m).

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

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
65
39
81
Manufacturing
74
95
111
Electricity, Gas, Water and Waste Services
18
23
26
Construction
21
215
214
Wholesale Trade
10
85
85
Retail Trade
103
90
156
Transport, Postal and Warehousing
61
162
170
Information Media and Telecommunications
33
39
54
Financial and Insurance Services
87
49
106
Rental, Hiring and Real Estate Services
94
126
158
Professional, Scientific and Technical Services
58
109
99
Other Selected Services
74
147
158
Total
231
406
435
New South Wales
122
231
257
Victoria
125
192
213
Queensland
99
213
231
South Australia
57
95
102
Western Australia
52
92
114
Tasmania
34
35
49
Northern Territory
8
26
28
Australian Capital Territory
8
19
21
Australia
231
406
435