Accommodation Survey: August 2009

Technical notes

Population

The target population for this survey is all 'geographic units' (called 'establishments' in this publication) that are classified as short-term (less than one month) commercial accommodation providers operating in New Zealand. In terms of the Australian and New Zealand Standard Industrial Classification 2006 (ANZSIC06), the target population is taken from class 4400 (accommodation), and the part of class 4520 (pubs, taverns and bars) that also provides accommodation.

The survey frame is all short-term commercial accommodation-providing geographic units belonging to an economically significant 'enterprise'. Economic significance is generally determined as being GST registered and having a turnover of at least $30,000 per annum.

Survey errors

This survey aims for 100 percent coverage of the population (a full census). In practice, however, an overall response rate of between 76 and 80 percent is usually achieved. The remaining units are given imputed values based upon the characteristics of similar establishments in the same or similar regions. Imputation introduces unknown errors into the estimates, and users of the data should bear this in mind. The size of these unknown errors is difficult to quantify.

Other errors occur for reasons such as respondent error, frame quality and errors in processing. While every effort is made to minimise these errors, they will still occur. It is not possible to quantify their effect.

Trend estimates

For any series, the survey estimates can be broken down into three components: trend, seasonal and irregular. While seasonally adjusted series have had the seasonal component removed, the trend series have had both the seasonal and the irregular components removed. Trend estimates reveal the underlying direction of movement in a series, and are likely to indicate turning points more accurately than seasonally adjusted estimates.

The accommodation trend series are calculated using the X-12-ARIMA seasonal adjustment package. They are based on optimal moving averages of the seasonally adjusted series, with an adjustment for outlying values. The X-12-ARIMA package is an updated version of X-11-ARIMA, developed by the U.S. Census Bureau.

The trend estimates towards the end of the series incorporate new data as it becomes available, and can therefore change as more observations are added to the series. Revisions can be particularly large if an observation is treated as an outlier in one month, but is found to be part of the underlying trend as further observations are added to the series. All trend estimates are subject to revisions each month, but normally only the last two or three estimates are likely to be substantially altered.

Trend estimates versus month-on-month comparisons

Trend estimates reveal the underlying direction of the movement in a series. In contrast, comparisons between one month and the same month in the previous year(s) do not take account of data recorded in between these periods, and are subject to one-off fluctuations. Reasons for fluctuations include changes in the timing of holidays, international crises, and large sporting and cultural events.

Seasonally adjusted estimates

The X-12-ARIMA package has been used to produce the seasonally adjusted estimates referred to in the Commentary text. Seasonal adjustment aims to eliminate the impact of regular seasonal events. These may be due to climatic effects (such as more guests staying in camping grounds during the summer) or calendar effects (such as holidays). This makes the data for adjacent months more comparable. All seasonally adjusted figures are subject to revision each month.

Further information about seasonal adjustment is available on the Statistics New Zealand website.

Classification of accommodation type

The predominant capacity provided determines the accommodation type. For instance, if a business provides both motel and camping ground accommodation, but the majority of its stay units are motel rooms, then it would be classified as a motel. The classification system used is the New Zealand Accommodation Classification, broadly defined below:

  • Hotels: includes both hotels and resorts
  • Motels: includes motor inns, apartments and motels
  • Hosted: includes private hotels, guest houses, bed and breakfasts, and holiday farm (farmstay) accommodation
  • Backpackers/hostels
  • Caravan parks/camping grounds.

Further information on the classification system is available on request.

Origin of guests

From November 2007, information on total domestic and international guest nights will be available on a monthly basis but the breakdown by region or country will no longer be available.

Other definitions

Business frame

A register (maintained by Statistics NZ) of all economically significant businesses operating in New Zealand from which the survey population is drawn.

Establishment

The smallest statistical unit operating within a single physical location and owned by a single enterprise. The term is used to represent what is usually called the 'geographic unit' in other Statistics NZ publications.

Guest night

A guest night is equivalent to one guest spending one night at an establishment. For example, a motel with 15 guests spending two nights would report provision of 30 guest nights of accommodation.

Stay unit

The term used to describe the unit of accommodation that is available to be charged out to guests (for example a powered site in a caravan park, a bed in a backpackers, a room in a hotel or motel).

Capacity (stay unit nights available)

This is the basic measure of an establishment's accommodation capacity. It is defined as one stay unit multiplied by one night. For example, 10 units in a motel available for guest use (whether occupied or not) for the full 31 days in July would have an accommodation capacity of 310 stay unit nights.

Occupancy rate

This derived variable is calculated by dividing stay unit nights occupied by stay unit nights available. In the case of the motel above, if six of its 10 units were occupied every night in July, it would have 6 x 31 = 186 stay unit nights occupied, and its occupancy rate would be 60 percent.

Average length of stay

This derived variable is calculated by dividing total guest nights by total guest first nights.

More information

For more information, follow the link from the Technical notes of this release on the Statistics NZ website.

Confidentiality

Data collected and information contained in this publication must conform to the provisions of the Statistics Act 1975. This requires that published information maintains the confidentiality of individual respondents.

Copyright

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Liability

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