5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Mar 2018 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 31/05/2018   
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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 $26,199 and the calculated standard error in this case is $384m. The standard error is then used to interpret the level estimate of $26,199.

For instance, the standard error of $384m indicates that:

  • There are approximately two chances in three that the real value falls within the range $25,815m to $26,583m ($26,199m ± $384m)
  • There are approximately 19 chances in 20 that the real value falls within the range $25,431m to $26,967m ($26,199m ± $768m)

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 2018 estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
45
37
61
Manufacturing
42
101
109
Electricity, Gas, Water and Waste Services
34
13
38
Construction
24
142
142
Wholesale Trade
7
60
61
Retail Trade
25
36
48
Transport, Postal and Warehousing
82
83
107
Information Media and Telecommunications
3
36
37
Financial and Insurance Services
9
53
54
Rental, Hiring and Real Estate Services
182
99
220
Professional, Scientific and Technical Services
20
71
70
Other Selected Services
55
105
116
Total
233
274
384
New South Wales
127
155
206
Victoria
91
122
153
Queensland
65
130
153
South Australia
21
41
50
Western Australia
91
82
129
Tasmania
7
33
35
Northern Territory
7
26
28
Australian Capital Territory
5
19
20
Australia
233
274
384


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 $32,238m and the next quarter the published level estimate is $26,199m.

In this example, the calculated standard error for the movement estimate is $444m. The standard error is then used to interpret the published movement estimate of $6,039m.

For instance, the standard error of $444m indicates that:
  • There are approximately two chances in three that the real movement over the two-quarter period falls within the range $5,595m to $6,483m ($6,039m ± $444m)
  • There are approximately 19 chances in 20 that the real movement falls within the range $5,151m to $6,927m ($6,039 m ± $888m)

The following table shows the standard errors for March quarter 2018 movement estimates.

Buildings and Structures
Equipment, Plant and Machinery
Total
$m
$m
$m
Mining
42
27
56
Manufacturing
24
120
122
Electricity, Gas, Water and Waste Services
44
17
46
Construction
22
167
167
Wholesale Trade
18
81
81
Retail Trade
49
37
62
Transport, Postal and Warehousing
84
151
173
Information Media and Telecommunications
4
19
19
Financial and Insurance Services
42
55
66
Rental, Hiring and Real Estate Services
167
158
229
Professional, Scientific and Technical Services
81
124
152
Other Selected Services
89
131
174
Total
237
341
444
New South Wales
149
195
262
Victoria
109
185
210
Queensland
123
152
194
South Australia
43
87
102
Western Australia
60
158
168
Tasmania
8
39
41
Northern Territory
4
21
21
Australian Capital Territory
39
18
41
Australia
237
341
444