D.1. Household surveys and services items of EBOPS 2010: travel, transportation and other services
7.19. Using a household survey to collect information in relation to residents travelling abroad (i.e., outbound travel) will serve the needs of the BOP (travel and passenger transport items) and those of tourism statistics, in particular with respect to international tourism consumption, including international passenger transport. Residents, as members of households, will be asked, among other questions, about their travel abroad, the circumstances and characteristics of the travel and the expenditures attached to them (products and values). It should be underlined that travel and tourism refer to individuals, not to households. Nevertheless, when persons travel together and belong to the same household, data on shared expenditure by the travel party can be collected. Households are used exclusively for selection purposes, but not for providing results; households, as such, do not travel.
7.20. The fact that household surveys are generally conducted in the home facilitates the possibility for the persons being interviewed to check information, such as credit card invoices. The interviewer can collect the information on paper questionnaires or an electronic device, making it possible to control the consistency of the information (see chapter 21). Such procedures can be costly. As a consequence, some countries use telephone interviews, a cheaper procedure, but with less possibility, however, of asking more sophisticated questions. The telephone interview could also be used as a first step in approaching respondents through simple questions, after which the respondents could be asked if they would agree to respond to a questionnaire with more probing questions.
7.21. The travel item of resident/non-resident trade in services statistics, as well as tourism consumption, is expenditure oriented. Compilers will need an estimate of the value of expenditures per person in a given period, and that value will vary depending on numerous factors. In addition, the information on the characteristics of those travelling and their travel itself may be of interest for compiling other variables. Compilers will therefore need the type of information shown in box 7.1. The information on the characteristics of travel might differ from person to person within the same household, even if they travelled together (e.g., their purpose of travel might be different, and also their expenditures).
7.22. Reference period Additionally, because of memory effects, the period of reference to be used, regarding both travel/trips and the expenditure associated with them, must be very short. The present Guide considers it good practice to use a month as a reference period in order to reduce telescopic errors (improper date assigned to trips) and recalling errors (improper characteristics and expenditure) (see box 7.2). As a consequence, because most persons might not have made any trip during such a short period of reference, the selected sample should be sufficiently large so as to collect enough valid information. A solution could be to ask about travel in the last x months and then deal with the memory effect by weighting up information relating to older travel.
7.23. Issues to consider For the process of selecting households, individuals and travel/trips, various possibilities are conceivable and each of has its advantages and disadvantages. Regarding the selection of households:
(a) All households might be selected with equal probability or with different probabilities, taking into consideration differences in propensity to travel (for the rural population, for instance, or when countries have a stratified universe according to level of income, as higher income is often positively correlated with the propensity to travel);
(b) A moving panel of households that is renewed periodically can be used, allowing the design of profiles of behaviour over time. However, persons who frequently travel, and thus are absent when requested to answer the survey, will tend to be substituted by more sedentary persons who travel less, thus skewing the results of the survey.
7.24. Regarding the selection of informants, options include the following:
(a) Select randomly one person within the household who will inform on his/her travel and expenditures. The drawback is that much of the cost of visiting a household will be wasted, particularly taking into consideration that travelling over a short period is not so frequent, so that the randomly selected person might not have travelled, but other persons of the household might have;
(b) Include only persons over a certain threshold (10 years of age, 15 years of age, etc.). While this appears to be an attractive option, small children usually travel with other persons of the household, and though children usually do not pay themselves for their expenditures, their participation in a travel party decreases the average expenditure per person per day of all members of the party;
(c) Include everybody. This is often the method followed.
7.25. Regarding the selection of travel, one of the following options is possible:
(a) All travel can be selected both for the description of the trips taken and the attached expenditures. Although that method is often followed, it can be a drawback, especially with a large questionnaire, when persons travel frequently; restricting travel to outbound trips would lower the reported frequency of travel;
(b) All trips can be counted (outbound and domestic, i.e., in relation to tourism information needs), but the characteristics of the trip and expenditure are collected for only one of them (usually the most recent one); that is the approach followed by most compilers.
Using a household survey to collect the above-mentioned information could be done in various ways. It is possible to attach a “travel/tourism” module to an existing household survey (usually, a labour force survey or an income and expenditure survey), or to a design specific procedures for observing the required variables. Because of the particularities of tourism and travel mentioned above, using a household survey is usually considered initially by countries. However, this does not result in obtaining all necessary data and should be complemented by a specific survey to observe tourism and travel. Further information is provided in the ITRS 2008 Compilation Guide
7.26. Data for such other BOP services items as services consumed by households online, downloaded or received by e-mail or telephone (e.g., legal services, medical advice, audiovisual or software downloads and gambling). Although households may easily identify the type of online purchases they make, it may be difficult for households to identify whether they are buying their services locally or importing a service, and from which country. An additional difficulty is that the country of billing or marketing may not necessarily be the one that is actually supplying the service to the household. Services provided through mode 4 could be easier to identify, as when the supplier of the service is physically present to render it. This identification of mode 4 transactions for relevant services could be particularly useful for the needs identified in the present Guide. However, it will be necessary to ensure that respondents understand the difference between an employment relationship and a service contract. Such information could be collected through existing household surveys, such as expenditure and income surveys, or a specialized survey on the use of the Internet or a telecommunications network by households, or could be collected by developing a specific module or survey. For all those services, sampling will be important to consider, as any household could potentially be a buyer of services. In addition, many of the payments will most probably be low, possibly below thresholds that have been established in the data collection system. Many of the recommendations provided above on the selection of households and informants to collect information on travel/tourism and transport are also relevant for other services. To summarize, although it may be appealing to approach households to collect data for payments for services other than travel/tourism expenditures or related information (including international passenger transport), compilers need to consider if such an approach would provide meaningful and exploitable results for compiling other BOP services items.
Next: D.2. Household surveys and (mode 4) receipts for exports of services
 However, it is also necessary to consider cost, burden and sparsity ofresponses . Alternatives to increasing the size of the sample may involve using auxiliary information to better target travellers in household surveys.
 Teresa Guardia and Sandra Garcia, “Memory effect in the Spanish domestic and outbound tourism survey (FAMILITUR)”, paper presented to the OECD ninth International Forum on Tourism Statistics, Paris, November 2008.