5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Dec 2017 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 01/03/2018   
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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 $32,170 and the calculated standard error in this case is $403m. The standard error is then used to interpret the level estimate of $32,170.

For instance, the standard error of $403m indicates that:

  • There are approximately two chances in three that the real value falls within the range $31,767m to $32,573m ($32,170m ± $403m)
  • There are approximately 19 chances in 20 that the real value falls within the range $31,364m to $32,976m ($32,170m ± $806m)

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 2017 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
61
37
74
Manufacturing
43
108
122
Electricity, Gas, Water and Waste Services
36
16
40
Construction
22
141
145
Wholesale Trade
19
76
79
Retail Trade
57
30
64
Transport, Postal and Warehousing
6
170
169
Information Media and Telecommunications
4
31
31
Financial and Insurance Services
26
59
67
Rental, Hiring and Real Estate Services
129
140
188
Professional, Scientific and Technical Services
85
115
123
Other Selected Services
102
105
149
Total
230
357
403
New South Wales
126
177
209
Victoria
80
169
192
Queensland
143
160
215
South Australia
37
78
85
Western Australia
46
135
147
Tasmania
3
21
21
Northern Territory
7
24
25
Australian Capital Territory
13
11
18
Australia
230
357
403



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 $28,903m and the next quarter the published level estimate is $32,170m.

In this example, the calculated standard error for the movement estimate is $430m. The standard error is then used to interpret the published movement estimate of $3,267m.

For instance, the standard error of $430m indicates that:
  • There are approximately two chances in three that the real movement over the two-quarter period falls within the range $2,837m to $3,697m ($3,267m ± $430m).
  • There are approximately 19 chances in 20 that the real movement falls within the range $2,407m to $4,127m ($3,267 m ± $860m)

The following table shows the standard errors for December quarter 2017 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
42
35
59
Manufacturing
31
86
95
Electricity, Gas, Water and Waste Services
43
21
50
Construction
22
178
182
Wholesale Trade
21
100
104
Retail Trade
89
85
132
Transport, Postal and Warehousing
10
196
196
Information Media and Telecommunications
10
27
30
Financial and Insurance Services
14
42
47
Rental, Hiring and Real Estate Services
88
115
136
Professional, Scientific and Technical Services
90
128
155
Other Selected Services
127
111
158
Total
208
375
430
New South Wales
143
253
306
Victoria
108
160
190
Queensland
102
180
201
South Australia
84
109
139
Western Australia
44
90
103
Tasmania
10
28
31
Northern Territory
7
26
28
Australian Capital Territory
12
16
21
Australia
208
375
430