5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, June 2011 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 01/09/2011   
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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 $34,389m and the calculated standard error in this case is $768m. The standard error is then used to interpret the level estimate of $34,389m.

For instance, the standard error of $768m indicates that:

  • There are approximately two chances in three that the real value falls within the range $33,621m to $35,157m ($34,389m ± $768m)
  • There are approximately 19 chances in 20 that the real value falls within the range $32,853m to $35,925m ($34,389m ± $1,536m)

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 June Quarter 2011 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
221
359
574
Manufacturing
48
97
113
Electricity, Gas, Water and Waste Services
7
22
23
Construction
9
205
204
Wholesale Trade
8
66
67
Retail Trade
13
66
67
Transport, Postal and Warehousing
40
194
200
Information Media and Telecommunications
2
15
15
Financial and Insurance Services
7
111
111
Rental, Hiring and Real Estate Services
426
103
423
Professional, Scientific and Technical Services
78
92
119
Other Selected Services
107
138
206
Total
506
478
768
New South Wales
91
242
248
Victoria
248
135
292
Queensland
374
238
418
South Australia
14
73
77
Western Australia
224
402
608
Tasmania
6
38
39
Northern Territory
65
14
65
Australian Capital Territory
2
13
14
Australia
506
478
768



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 $27,265m and the next quarter the published level estimate is $34,389m.

In this example the calculated standard error for the movement estimate is $651m. The standard error is then used to interpret the published movement estimate of $7,124m.

For instance, the standard error of $651m indicates that:
  • There are approximately two chances in three that the real movement over the two quarter period falls within the range $6,473m to $7,775m ($7,124m ± $651m).
  • There are approximately nineteen chances in twenty that the real movement falls within the range $5,822m to $8,426m ($7,124m ± $1,302m)

The following table shows the standard errors for June Quarter 2011 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
42
373
386
Manufacturing
30
110
118
Electricity, Gas, Water and Waste Services
6
26
26
Construction
9
309
309
Wholesale Trade
7
77
78
Retail Trade
22
94
102
Transport, Postal and Warehousing
30
167
164
Information Media and Telecommunications
4
8
10
Financial and Insurance Services
6
110
110
Rental, Hiring and Real Estate Services
283
95
303
Professional, Scientific and Technical Services
54
81
94
Other Selected Services
101
149
208
Total
319
564
651
New South Wales
60
216
221
Victoria
273
229
358
Queensland
93
245
273
South Australia
18
55
59
Western Australia
74
413
437
Tasmania
7
40
43
Northern Territory
23
25
35
Australian Capital Territory
2
24
24
Australia
319
564
651