Since 2005-2006, the WBES implemented by the Enterprise Analysis Unit follow the Global Methodology. Earlier datasets from differing survey instruments have been matched to a standard instrument for dissemination on the website and data portal. Note that data users should exercise caution when comparing raw data and point estimates between surveys that did and surveys that did not adhere to the WBES Global Methodology.
Private contractors, selected competitively through the World Bank procurement process, conduct the WBES on behalf of the World Bank. The mode of data collection is face-to-face interviews, and anonymity is never compromised.
The WBES is answered by business owners and top managers. The survey respondents might sometimes involve accountants and human resource managers to answer some questions.
Occasionally, for a few economies, other sectors are included on demand such as education or health. These are included as additional strata to preserve the comparability to the full global dataset by excluding these additional sectors.
The standard WBES questionnaire covers over 15 topics, including firm characteristics, gender participation, access to finance, annual sales, among others. See the questionnaire here.
Over 90% of the questions are fact-based, while the remaining 10% assess the respondents’ opinions on obstacles to their firm’s growth and performance.
The WBES uses stratified random sampling, with the following strata:
The Sampling Note provides the rationale for the sample sizes.
Ideally, the survey sample frame is derived from the universe of eligible firms obtained from the economy’s statistical office. Sometimes the master list of firms is obtained from other government agencies such as tax or business licensing authorities. In some cases, the list of firms is obtained from business associations or marketing databases. In some cases, the list of firms is obtained form business associations or marketing databases, provided that they are comprehensive.
The WBES also provides panel data, i.e., interviews with the same firms across multiple years. When conducting a new WBES, maximal effort is expended to re-interview at least half of the firms from the prior WBES. For these panel firms, sampling weights are adjusted to consider the resulting altered probabilities of inclusion in the sample frame.
* Please note that from August 2022, the WBES uses ISIC Rev. 4 (instead of Rev.3.1) for categorizing business activity. Henceforth, businesses under Section M of ISIC Rev. 4, i.e., professional, scientific, and technical activities, became eligible to participate.
The Informal Sector Enterprise Surveys follow a rigorous survey methodology that fits the unique characteristics of the unregistered businesses sector. The surveys use tailored questionnaires and a geographically-based sampling strategy, Adaptive Cluster Sampling, which discovers these businesses while also obtaining representative samples.
Note that as of May 2025, all indicators are calculated using weak survey weights (wweak), which are inclusive of interview refusals and unavailable businesses. City Profiles prior to May 2025 have not been updated. Early surveys in Zimbabwe and Mozambique are not affected by the change.
Private contractors conduct the WBES on behalf of the World Bank. The mode of data collection is face-to-face interviews, and anonymity is never compromised.
The Informal Sector Enterprise Survey is answered by entrepreneurs of unregistered businesses.
The topics in the questionnaire generally include:
The Informal Sector Enterprise Surveys use a two-stage sampling process.
The first stage uses a methodology called Adaptive Cluster Sampling (ACS). ACS requires a well-defined geographical area; for these surveys, it is typically an urban center. On a map of this delineated area, the Enterprise Analysis Unit creates a grid of evenly sized squares, called Block Areas or BAs, on the map and selects an initial sample of BAs at random (often within strata) without replacement. Within an enumerated BA, some basic information is listed on all encountered informal businesses, including through observation for those that refuse the exercise or those that are unavailable at the time of fieldwork. ACS is ‘adaptive’ in the sense that, using a pre-defined threshold number of informal businesses, all neighboring BAs of a BA that meets the threshold are subsequently sampled until there are no BAs that meet this expansion requirement. This process allows for first-stage weights to be calculated, allowing the Informal Sector Enterprise Surveys to be geographically representative of the urban areas where it is implemented. Full details of the methodology are provided in Aga et. al (2023).
The second stage of Informal Sector Enterprise Surveys involves the random selection of informal businesses within a BA to participate in an interview that lasts approximately 20–25 minutes. This interview consists of a standardized and tested questionnaire, properly designed for the circumstances of interviewing informal businesses. Aberra et al. (2022) provide further information on how these interviews are conducted. The selection for these longer interviews is done randomly and in real time. . As a result, a second-stage weight can be applied. Aga et. al (2022) provide some additional information on the selection process for the interviews, including adjustments to these weights based on assumptions about refusals and unavailable businesses.
Note that prior to 2015, the first stage sampling was done through a convenience sample approach, where a block is chosen randomly in a neighborhood of interest; enumerators then followed a path according to a predetermined set of instructions, enumerating every informal business encountered. Unlike the currently used two-stage sampling process, a convenience sample approach does not render a representative sample of informal businesses.
All the datasets are available through the portal, including documentation on the survey implementation details. These Implementation Reports contain information on the fieldwork, sampling procedures, dataset structure (including variable names), as well as information specific to the survey’s implementation.
The Micro Enterprise Surveys provide data for businesses with 1-4 workers across 35 economies around the world.
Other business surveys carried out by the Enterprise Analysis Unit include:
All datasets for these surveys are available in the data portal.
Private contractors conduct the Micro Enterprise Surveys and other surveys on behalf of the World Bank. Surveys are usually carried out in cooperation with business organizations and government agencies promoting job creation and economic growth, but anonymity is never compromised. The mode of data collection generally is face-to-face interviews (in-person or virtual).
The Micro Enterprise Surveys follow the methodology of the Formal Sector Enterprise Surveys.
For other surveys, the respondents vary depending on the objective of the specific survey. All the relevant information for each survey is available in the documentation of that survey in the data portal.
The Micro Enterprise Surveys follow the methodology of the Formal Sector Enterprise Surveys.
For other surveys, the questions vary depending on the objective of the specific survey. All the relevant information for each survey is available in the documentation of that survey in the data portal.
The Micro Enterprise Surveys follow the methodology of the Formal Sector Enterprise Surveys.
For other surveys, the methodology varies depending on the objective of the specific survey. All the relevant information for each survey is available in the documentation of that survey in the data portal.
