EXPLANATORY NOTES

INTRODUCTION

1 This publication summarises results from the 2011 State Supplementary Survey, Household Water and Energy Use. The survey was conducted throughout Victoria during the two weeks commencing 9^th October 2011. This is the second time in the last five years that state data about household water and energy use in Victoria has been collected in a State Supplementary Survey. The prior survey of Household Water, Energy Use and Conservation was conducted in 2009.

SURVEY SAMPLE DESIGN

2 The survey was conducted as a supplement to the Australian Bureau of Statistics (ABS) Monthly Population Survey (MPS). The MPS is based on a multistage area sample of private dwellings (houses, flats, etc) and a list sample of non-private dwellings (hotels, motels etc). The 2011 State Supplementary Survey was conducted using seven-eighths of the full sample of private dwellings in Victoria that were included in the MPS.

3 For details of the design, scope and coverage of the MPS, readers should refer to the Information Paper: Labour Force Survey Sample Design, 2007 (cat. no. 6269.0), and any recent edition of the ABS publication Labour Force, Australia (cat. no. 6202.0).

4 The Labour Force Statistical Regions used for the survey are based on the 2006 Australian Standard Geographical Classification. For further information please see Chapter 5 Statistical Region Structure in the Statistical Geography Volume 1 - Australian Standard Geographical Classification (ASGC), Jul 2006 (cat. no. 1216.0). For maps of the Labour Force Statistical Regions please see Australian Labour Market Statistics, Jul 2009 (cat. no. 6105.0).

SCOPE

5 Information was collected via interview from any responsible adult aged 18 years and over in the household.

The following dwellings were excluded:

§ unoccupied private dwellings

§ non-private dwellings such as hospitals, hotels, motels and prisons

The following people were excluded:

§ persons aged under 18 years

§ members of the permanent defence forces

§ certain diplomatic personnel of overseas governments, customarily excluded from censuses and surveys

§ overseas residents in Australia

§ members of non-Australian defence forces (and their dependents)

§ those who were visitors to a private dwelling

§ those who did not have a resident parent/guardian in the household

§ those in very remote Indigenous Community Frame (ICF) Collection Districts (CD)

6 The survey was conducted in both urban and rural areas throughout Victoria, and excluded people living in very remote areas who would otherwise have been within the scope of the survey. The exclusion of these people had only a minor impact on any aggregate estimates.

7 Melbourne's public transport network is divided into two main Metropolitan Public Transport Zones. The geographic scope and detail of the public transport tables has been limited to CDs within Melbourne Metropolitan Public Transport Zones 1 and 2. Areas beyond the Melbourne Major Statistical Region were outside the scope of the public transport tables. CDs were aligned to the Metropolitan Public Transport Zone which had the majority of the area within that CD. CDs which were mostly in the Metropolitan Public Transport Zone boundary overlap (where stations and stops can be used as either Zone 1 or Zone 2) were aligned to Zone 1 on the presumption that most public transport travel is to and from the city centre, and as such, people in these CDs were more likely to have purchased a Zone 1 ticket. CDs outside Zone 2 but within the Melbourne Major Statistical Region were excluded from the public transport tables.

COVERAGE

8 Coverage rules were applied to ensure that each person was associated with only one dwelling, and hence had only one chance of selection in the survey.

9 Information was sought from 5,143 people in Victoria and a full response was collected from 4,624 (89.9%).

DATA COLLECTION

10 Information was collected by either a face-to-face or telephone interview conducted over a two-week period during October 2011. Information was collected from any responsible adult in the household aged 18 years and over, who was asked to respond on behalf of the household for the water and energy use topics and for a randomly selected person in the household for the public transport use topic.

11 Data was collected on the number of persons in the household. This includes all children (aged under 18 years) within the household plus the number of adults in the scope of the Labour Force Survey.

REFERENCE PERIOD

12 The reference period for most tables within the data cubes is October 2011. The exceptions were :

§ In the Data Cube for Public Transport: Tables 1a, 1b, 2a, 2b, 4a and 4b - the reference period is the month prior to October 2011.

§ In the Data Cube for Energy: Tables 16a and 16b - the reference period is the month prior to October 2011.

§ In the Data Cube for Energy: Tables 4a, 4b, 7a, 7b, 8a, 8b, 11a, 11b, 12a and 12b - the reference period is the 12 months prior to October 2011.

EFFECTS OF ROUNDING

13 Estimates have been rounded, and discrepancies may occur between sums of the component items and totals.

EQUIVALISED WEEKLY HOUSEHOLD INCOME

14 Equivalence scales are used to adjust the actual incomes of households in a way that enables the analysis of the relative wellbeing of people living in households of different size and composition. For example, it would be expected that a household comprising two people would normally need more income than a lone person household if all the people in the two households are to enjoy the same material standards of living. Adopting a per capita analysis would address one aspect of household size difference, but would address neither compositional difference (i.e. the number of adults compared with the number of children) nor the economies derived from living together. When household income is adjusted according to an equivalence scale, the equivalised income can be viewed as an indicator of the economic resources available to a standardised household. For a lone person household, it is equal to income received. For a household comprising more than one person, equivalised income is an indicator of the household income that would be required by a lone person household in order to enjoy the same level of economic wellbeing as the household in question. The equivalence scale used in this publication was developed for the Organisation for Economic Co-operation and Development and is referred to as the "modified OECD" equivalence scale. It is widely accepted among Australian analysts of income distribution. The scale allocates 1.0 point for the first adult (aged 15 years and over) in a household; 0.5 for each additional adult; and 0.3 for each child. Equivalised household income is derived by dividing total household income by the sum of the equivalence points allocated to household members. For example, if a household received combined gross income of $2,100 per week and comprised two adults and two children (combined household equivalence points of 2.1), the equivalised gross household income would be calculated as $1,000 per week. For more information on the use of equivalence scales, see Household Income and Distribution, Australia (cat. no. 6523.0). COMPARATIVE DATA 15 Some comparisons have been made in this publication to data collected in a previous supplementary survey - Household Water, Energy Use and Conservation, Victoria, Oct 2009 (cat. no. 4602.2). Any references to the previous survey are noted in the text as (2009) and are only included where the definitions of categories in both the surveys are similar.

ACKNOWLEDGEMENT

16 ABS publications draw extensively on information provided freely by individuals, businesses, governments and other organisations. Their continued cooperation is very much appreciated. Without it, the wide range of statistics published by the ABS would not be available. Information received by the ABS is treated in strict confidence as required by the Census and Statistics Act (1905).

RELATED PUBLICATIONS

17 The ABS has been conducting surveys related to the topic of Household Water and Energy Use on an irregular basis. Previous ABS surveys related to Household Water and Energy Use used a variety of sampling methods, estimation methods, concepts, data item definitions and classifications. These include:

• Environmental Issues: Energy Use and Conservation, Mar 2011, cat. no. 4602.0.55.001
• Australia's Environment: Issues and Trends, Jan 2010, cat. no. 4613.0
• Household Water, Energy Use and Conservation, Oct 2009, cat . no. 4602.2
• Environmental Issues: Waste Management and Transport Use, Mar 2009, cat. no. 4602.0.55.00
• Environmental Issues: Energy Use and Conservation, Mar 2008, cat. no. 4602.0.55.001

The ABS produces a wide range of publications relating to demographic, housing, environment and transport statistics. Current publications and other products released by the ABS are available from the Statistics View. The ABS also issues a daily Release Advice on the ABS website www.abs.gov.au which details products to be released in the week ahead.

18 The Household Water and Energy Use survey is not part of the ongoing ABS MPS program. Extreme caution must be used when comparing the 2011 survey with other related publications as differences in scope and methodology exist.

DATA AVAILABLE ON REQUEST

19 Inquiries about these statistics and more detailed statistics than those presented in the publication should be made by contacting the National Information and Referral Service on 1300 135 070 or Halley Coldicott in Melbourne on (03) 9615 7772.