5625.0 - Private New Capital Expenditure and Expected Expenditure, Australia, Mar 2010
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 27/05/2010
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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 \$24,030m and the calculated standard error in this case is \$629m. The standard error is then used to interpret the level estimate of \$24,030m.

For instance, the standard error of \$629m indicates that:

• There are approximately two chances in three that the real value falls within the range \$23,401m to \$24,659m (\$24,030m ± \$629m)
• There are approximately 19 chances in 20 that the real value falls within the ranges \$22,772m to \$25,288m (\$24,030m ± \$1,364m)

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 2010 estimates.

 Buildings and Structures Equipment, Plant and Machinery Total \$m \$m \$m Mining 38 34 60 Manufacturing 25 105 116 Electricity, Gas, Water and Waste Services 4 18 18 Construction 24 276 283 Wholesale Trade 4 126 127 Retail Trade 50 88 101 Transport, Postal and Warehousing 23 86 90 Information Media and Telecommunications 7 29 31 Financial and Insurance Services 14 81 85 Rental, Hiring and Real Estate Services 311 360 515 Professional, Scientific and Technical Services 8 83 85 Other Selected Services 103 106 147 Total 331 509 629 New South Wales 171 251 316 Victoria 289 384 500 Queensland 162 114 196 South Australia 11 114 116 Western Australia 52 155 158 Tasmania 4 12 13 Northern Territory 9 63 63 Australian Capital Territory 5 4 6 Australia 331 509 629

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 \$29,853m and the next quarter the published level estimate is \$24,030m. In this example the calculated standard error for the movement estimate is \$746m. The standard error is then used to interpret the published movement estimate of \$5,823m.

For instance, the standard error of \$746m indicates that:
• There are approximately two chances in three that the real movement over the two quarter period falls within the range \$5,077m to \$6,569m (\$5,823m ±\$746m)
• There are approximately nineteen chances in twenty that the real movement falls within the range \$4,331m to \$7,315m (\$5,823m ± \$1,492m).

The following table shows the standard errors for March Quarter 2010 estimates.

 Buildings and Structures Equipment, Plant and Machinery Total \$m \$m \$m Mining 40 89 92 Manufacturing 39 186 193 Electricity, Gas, Water and Waste Services 5 27 28 Construction 30 303 308 Wholesale Trade 49 144 154 Retail Trade 55 115 124 Transport, Postal and Warehousing 23 202 199 Information Media and Telecommunications 7 24 27 Financial and Insurance Services 22 102 107 Rental, Hiring and Real Estate Services 454 267 539 Professional, Scientific and Technical Services 41 103 114 Other Selected Services 117 144 181 Total 488 516 746 New South Wales 146 341 372 Victoria 281 295 377 Queensland 187 165 254 South Australia 38 85 92 Western Australia 208 190 268 Tasmania 3 36 36 Northern Territory 8 49 50 Australian Capital Territory 207 52 212 Australia 488 516 746