5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Dec 2012 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 28/02/2013   
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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 $44,127m and the calculated standard error in this case is $610m. The standard error is then used to interpret the level estimate of $44,127m.

For instance, the standard error of $610m indicates that:

  • There are approximately two chances in three that the real value falls within the range $43,517m to $44,737m (44,127m $610m)
  • There are approximately 19 chances in 20 that the real value falls within the range $42,907m to $45,347m (44,127m $1,220m)

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 2012 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m

Mining
457
58
458
Manufacturing
42
62
87
Electricity, Gas, Water and Waste Services
38
7
38
Construction
21
234
232
Wholesale Trade
41
67
87
Retail Trade
6
54
54
Transport, Postal and Warehousing
74
123
152
Information Media and Telecommunications
1
23
23
Financial and Insurance Services
27
22
35
Rental, Hiring and Real Estate Services
99
154
194
Professional, Scientific and Technical Services
44
97
107
Other Selected Services
63
102
128
Total
483
365
610
New South Wales
85
170
201
Victoria
53
111
133
Queensland
450
198
508
South Australia
57
48
84
Western Australia
148
193
245
Tasmania
44
39
74
Northern Territory
2
10
11
Australian Capital Territory
1
32
31
Australia
483
365
610




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 $40,284m and the next quarter the published level estimate is $44,127m.

In this example the calculated standard error for the movement estimate is $371m. The standard error is then used to interpret the published movement estimate of $3,843m.

For instance, the standard error of $371m indicates that:
  • There are approximately two chances in three that the real movement over the two quarter period falls within the range $3,472m to $4,214m ($3,843m $371m).
  • There are approximately nineteen chances in twenty that the real movement falls within the range $3,101m to $4,585m ($3,843 $742m)

The following table shows the standard errors for December Quarter 2012 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m

Mining
71
100
126
Manufacturing
37
72
95
Electricity, Gas, Water and Waste Services
18
6
18
Construction
54
208
209
Wholesale Trade
36
65
79
Retail Trade
38
52
65
Transport, Postal and Warehousing
83
110
136
Information Media and Telecommunications
4
21
22
Financial and Insurance Services
25
25
39
Rental, Hiring and Real Estate Services
170
116
199
Professional, Scientific and Technical Services
44
130
131
Other Selected Services
75
100
135
Total
229
321
371
New South Wales
172
169
222
Victoria
97
113
156
Queensland
79
169
187
South Australia
63
62
88
Western Australia
80
166
177
Tasmania
48
58
92
Northern Territory
5
15
17
Australian Capital Territory
5
29
28
Australia
229
321
371