5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Mar 2015 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 28/05/2015   
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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 $32,381m and the calculated standard error in this case is $482m. The standard error is then used to interpret the level estimate of $32,381m.

For instance, the standard error of $482m indicates that:

  • There are approximately two chances in three that the real value falls within the range $31,899m to $32,863m ($32,381m ± $482m)
  • There are approximately 19 chances in 20 that the real value falls within the range $31,417m to $33,345m ($32,381m ± $964m)

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 March Quarter 2015 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
37
92
102
Manufacturing
43
126
134
Electricity, Gas, Water and Waste Services
38
47
59
Construction
67
276
290
Wholesale Trade
17
33
42
Retail Trade
48
70
91
Transport, Postal and Warehousing
72
136
168
Information Media and Telecommunications
-
25
25
Financial and Insurance Services
42
24
55
Rental, Hiring and Real Estate Services
131
199
205
Professional, Scientific and Technical Services
10
82
82
Other Selected Services
104
109
160
Total
202
449
482
New South Wales
66
225
239
Victoria
46
209
222
Queensland
129
259
298
South Australia
67
86
114
Western Australia
134
159
218
Tasmania
-
28
29
Northern Territory
4
10
13
Australian Capital Territory
-
26
26
Australia
202
449
482
- nil or rounded to zero (including null cells)



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 $41,657m and the next quarter the published level estimate is $32,381m.

In this example the calculated standard error for the movement estimate is $467m. The standard error is then used to interpret the published movement estimate of $9,276m.

For instance, the standard error of $467m indicates that:
  • There are approximately two chances in three that the real movement over the two quarter period falls within the range $8,809m to $9,743m ($9,276m ± $467m).
  • There are approximately 19 chances in 20 that the real movement falls within the range $8,342m to $10,210m ($9,276m ± $934m)

The following table shows the standard errors for March Quarter 2015 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
40
95
108
Manufacturing
39
112
112
Electricity, Gas, Water and Waste Services
45
18
50
Construction
56
268
273
Wholesale Trade
77
70
107
Retail Trade
35
109
110
Transport, Postal and Warehousing
71
126
150
Information Media and Telecommunications
36
21
41
Financial and Insurance Services
39
47
56
Rental, Hiring and Real Estate Services
119
200
230
Professional, Scientific and Technical Services
31
115
121
Other Selected Services
79
144
159
Total
203
417
467
New South Wales
102
294
326
Victoria
74
188
219
Queensland
122
221
251
South Australia
67
118
135
Western Australia
74
137
159
Tasmania
3
31
31
Northern Territory
63
14
59
Australian Capital Territory
8
35
36
Australia
203
417
467