5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Dec 2011
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 01/03/2012
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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 \$40,608m and the calculated standard error in this case is \$688m. The standard error is then used to interpret the level estimate of \$40,608m.

For instance, the standard error of \$688m indicates that:

• There are approximately two chances in three that the real value falls within the range \$39,920m to \$41,296m (\$40,608m ± \$688m)
• There are approximately 19 chances in 20 that the real value falls within the range \$39,232m to \$41,984m (\$40,608 ± \$1,376m)

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 2011 estimates.

 Buildings and Structures Equipment, Plant and Machinery Total \$m \$m \$m Mining 304 207 493 Manufacturing 61 126 147 Electricity, Gas, Water and Waste Services 10 54 61 Construction 5 199 199 Wholesale Trade 61 77 112 Retail Trade 21 42 47 Transport, Postal and Warehousing 51 144 158 Information Media and Telecommunications 1 10 10 Financial and Insurance Services 23 38 50 Rental, Hiring and Real Estate Services 179 103 201 Professional, Scientific and Technical Services 96 117 158 Other Selected Services 72 104 135 Total 382 442 688 New South Wales 136 197 235 Victoria 92 141 167 Queensland 137 172 232 South Australia 13 93 94 Western Australia 330 257 556 Tasmania 3 44 44 Northern Territory 2 12 12 Australian Capital Territory 5 10 12 Australia 382 442 688

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 \$35,683m and the next quarter the published level estimate is \$40,608m.

In this example the calculated standard error for the movement estimate is \$527m. The standard error is then used to interpret the published movement estimate of \$4,925m.

For instance, the standard error of \$527m indicates that:
• There are approximately two chances in three that the real movement over the two quarter period falls within the range \$4,398m to \$5,452m (\$4,925m ± \$527m).
• There are approximately nineteen chances in twenty that the real movement falls within the range \$3,871m to \$5,979m (\$4,925m ± \$1054m)

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

 Buildings and Structures Equipment, Plant and Machinery Total \$m \$m \$m Mining 60 200 208 Manufacturing 63 117 139 Electricity, Gas, Water and Waste Services 6 38 41 Construction 15 199 197 Wholesale Trade 15 98 98 Retail Trade 7 50 50 Transport, Postal and Warehousing 33 138 141 Information Media and Telecommunications 1 20 20 Financial and Insurance Services 12 46 46 Rental, Hiring and Real Estate Services 278 105 313 Professional, Scientific and Technical Services 32 119 119 Other Selected Services 93 178 197 Total 314 457 527 New South Wales 119 264 273 Victoria 247 191 323 Queensland 125 184 224 South Australia 18 47 52 Western Australia 96 247 266 Tasmania 3 63 63 Northern Territory 3 12 12 Australian Capital Territory 2 17 16 Australia 314 457 527