Informal Survey 2010

The Informal Surveys are conducted in selected urban centers, which are intended to coincide with the locations for the implementation of the main Enterprise Surveys. The overall number of interviews is pre-determined.

In Peru, the urban centers identified were Lima and Arequipa. The target sample for both urban centers was 240 interviews.

Sampling in the Informal Surveys is conducted within clearly delineated sampling zones, which are geographically determined divisions within each urban center. Sampling zones are defined at the beginning of fieldwork, and are delineated according to the concentration and geographical dispersion of informal business activity.

The number of sampling areas, and the geographical area they contain, is determined with the goal that each sector will yield four effective interviews.

In Peru, each sampling area was designed to contain a physical area, on average, of no less than the equivalent of eight city blocks. These sampling areas may or may not correspond to the administrative districts of the urban center.

In both Lima and Arequipa, for a total of 240 interviews in each city, 60 sampling areas were identified (240/4 = 60 sampling areas), respectively.

In order to provide information on diverse aspects of the informal economy, the sample is designed to have equal proportions of services and manufacturing (50:50). These sectors are defined by responses provided by each informal business to a question on the business's main activity included in the screener portion of the questionnaire.

As a general rule, services must constitute an ongoing business enterprise and so exclude the sale of manual labor Manufacturing activity in the informal sector includes business activity requiring inputs and/or intermediate goods. Thus, for example, the processing of coffee, sugar, oil, dried fruit, or other processed foods is considered manufacturing, while the simple selling of these goods falls under services. If an informal business conducts a mixture of these activities, the business is considered under the manufacturing stratum.

Each sampling zone was designed with the goal of obtaining two interviews in services and two interviews in manufacturing. In order to ensure a degree of geographical dispersion within each sampling zone, two starting points were identified.

Each starting point was designed to correspond to five city blocks, which were numbered sequentially. The first starting point was identified as Starting
Point A and the second as Starting Point B.

Proceeding from each starting point, interviewers were instructed to begin on block 1, defining the starting block and corner. Each interviewer was instructed to attempt to achieve two interviews from each starting point, ideally one interview in manufacturing and one in services.

Interviewers were instructed to proceed clockwise around block 1 from Starting Point A; if the target interviews were not achieved, interviewers proceeded to block 2, Starting Point A, and so forth until completing a circuit of block 5. After achieving two interviews from Starting Point A, interviewers were instructed to cease work in the blocks assigned to that given Starting Point and repeat the sameprocedure from Starting Point B, beginning with block 1.

Using local knowledge, within each block all houses and shops were checked for unregistered businesses, following the pre-fixed route described above, until the
allotted quota of interviews for each starting point was reached. Often interviewers used referrals by neighbors and locals in order to identify informal businesses. When a referral was obtained, the pre-determined route was followed until reaching the address of the referral. It should be noted that when referrals were obtained, interviewers were instructed to maintain the sampling procedure noted above; i.e., in the case that an interviewer encountered an informal business in the process of following a referral, an attempt was made to interview the former business first.

Each sampling zone, including its two starting points, were marked using Google maps, with the GPS coordinates of the starting points being systematically recorded.

Additionally, when obtaining a complete interview, the exact address of the informal business (or where the interview took place) was registered by the interviewer. Once in the office, this address was searched in Google maps, and its GPS coordinates were registered in a fieldwork report.

If no address was immediately available, using local knowledge, the GPS coordinates were determined using imaging via Google maps. In order to preserve confidentiality, the exact coordinates of businesses are not published.

Due to issues of non-response, in the process of fieldwork, the implementing contractor was unable to obtain the targeted four interviews in each of the originally delineated sampling areas.

As a result, replacement sampling areas were delineated, ex post. In sum, there were 70 sampling areas (60 original, 10 replacement) in Arequipa and 72 zones in Lima (60 original, 12 replacement).

Complete information regarding the sampling methodology as well as maps of starting points can be found in "Description of Peru Informal Survey Implementation" and "Mapping of starting points for sampling in Peru Informal Survey 2010" in "Technical Documents" folder.