5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Sep 2014 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 27/11/2014   
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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 $38,853m and the calculated standard error in this case is $521m. The standard error is then used to interpret the level estimate of $38,853m.

For instance, the standard error of $521m indicates that:

  • There are approximately two chances in three that the real value falls within the range $38,332m to $39,374m ($38,853m ± $521m)
  • There are approximately 19 chances in 20 that the real value falls within the range $37,811m to $39,895m ($38,853m ± $1,042m)

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 2014 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
28
85
108
Manufacturing
56
52
77
Electricity, Gas, Water and Waste Services
54
20
57
Construction
25
191
191
Wholesale Trade
17
63
67
Retail Trade
47
114
122
Transport, Postal and Warehousing
14
159
158
Information Media and Telecommunications
33
11
33
Financial and Insurance Services
42
52
68
Rental, Hiring and Real Estate Services
196
218
293
Professional, Scientific and Technical Services
24
108
122
Other Selected Services
121
111
173
Total
270
412
521
New South Wales
123
208
260
Victoria
66
128
159
Queensland
116
262
301
South Australia
165
50
169
Western Australia
119
157
195
Tasmania
22
41
46
Northern Territory
2
43
44
Australian Capital Territory
4
55
56
Australia
270
412
521



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 $40,866m and the next quarter the published level estimate is $38,853m.

In this example the calculated standard error for the movement estimate is $519m. The standard error is then used to interpret the published movement estimate of -$2,013m.

For instance, the standard error of $519m indicates that:
  • There are approximately two chances in three that the real movement over the two quarter period falls within the range -$2,532m to -$1,494m (-$2,013m ± $519m).
  • There are approximately 19 chances in 20 that the real movement falls within the range -$3,051m to -$975m (-$2,013m ± $1,038m)

The following table shows the standard errors for September Quarter 2014 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
32
62
54
Manufacturing
60
99
117
Electricity, Gas, Water and Waste Services
46
22
48
Construction
21
211
211
Wholesale Trade
38
69
83
Retail Trade
47
128
135
Transport, Postal and Warehousing
25
180
186
Information Media and Telecommunications
33
8
32
Financial and Insurance Services
37
64
58
Rental, Hiring and Real Estate Services
220
150
284
Professional, Scientific and Technical Services
30
102
102
Other Selected Services
101
169
199
Total
264
446
519
New South Wales
100
266
287
Victoria
127
172
225
Queensland
99
238
255
South Australia
137
68
150
Western Australia
139
133
203
Tasmania
11
37
40
Northern Territory
2
42
43
Australian Capital Territory
4
55
55
Australia
264
446
519