5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Sep 2017 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 30/11/2017   
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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 $28,601 and the calculated standard error in this case is $475m. The standard error is then used to interpret the level estimate of $28,601.

For instance, the standard error of $475m indicates that:

  • There are approximately two chances in three that the real value falls within the range $28,126m to $29,076m ($28,601m ± $475m)
  • There are approximately 19 chances in 20 that the real value falls within the range $27,651m to $29,551m ($28,601m ± $950m)

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 2017 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
53
17
65
Manufacturing
27
114
118
Electricity, Gas, Water and Waste Services
68
28
74
Construction
58
161
176
Wholesale Trade
11
74
74
Retail Trade
77
74
113
Transport, Postal and Warehousing
10
178
179
Information Media and Telecommunications
13
6
15
Financial and Insurance Services
22
53
61
Rental, Hiring and Real Estate Services
112
110
168
Professional, Scientific and Technical Services
29
89
98
Other Selected Services
104
92
145
Total
214
389
475
New South Wales
71
239
264
Victoria
111
156
200
Queensland
99
161
193
South Australia
96
93
138
Western Australia
66
80
104
Tasmania
11
25
29
Northern Territory
6
8
11
Australian Capital Territory
2
11
11
Australia
214
389
475



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 $30,675m and the next quarter the published level estimate is $28,601m.

In this example, the calculated standard error for the movement estimate is $491m. The standard error is then used to interpret the published movement estimate of $2,074m.

For instance, the standard error of $491m indicates that:
  • There are approximately two chances in three that the real movement over the two-quarter period falls within the range $1,583m to $2,565m ($2,074m ± $491m).
  • There are approximately 19 chances in 20 that the real movement falls within the range $1,092m to $3,056m ($2,074 m ± $982m)

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

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
21
46
45
Manufacturing
32
100
103
Electricity, Gas, Water and Waste Services
69
20
72
Construction
63
256
238
Wholesale Trade
38
97
107
Retail Trade
104
100
144
Transport, Postal and Warehousing
24
262
268
Information Media and Telecommunications
9
29
30
Financial and Insurance Services
12
42
44
Rental, Hiring and Real Estate Services
84
108
134
Professional, Scientific and Technical Services
35
130
137
Other Selected Services
83
148
179
Total
197
471
491
New South Wales
82
298
321
Victoria
97
230
244
Queensland
103
246
275
South Australia
64
88
113
Western Australia
82
107
140
Tasmania
12
16
20
Northern Territory
18
20
25
Australian Capital Territory
5
14
14
Australia
197
471
491