Discussion and Recommendations

Each methodology presented in this toolkit has its inherent strengths and weaknesses, and the appropriateness of each will vary based on the particulars of a given research project. Before selecting an approach, it is important to carefully consider a number of factors.

The first of these is the research aim or aims of the project. Multiple research aims are likely to winnow the set of acceptable methods available. For example, although the total consumption‒recorded supply approach may be suitable for sizing the unrecorded market as a whole, a population-based survey and / or value chain analysis would be more appropriate when another aim is to determine the composition of the market. In some cases, multiple research aims may necessitate the implementation of multiple approaches.

In addition, it is important to identify available and reliable secondary data. In many cases, this alone will dictate whether desk research, field research, or both are necessary.

Another consideration concerns the relevant market, socio-cultural, and economic aspects of the geographical locality to be studied.

A final, but far from trivial, consideration is the resources available in terms of time, budget, and relevant methodological expertise. Field research approaches often require greater time and budgetary commitments, which may rule out their appropriateness for certain projects. That said, where desk research is not a suitable option given the research question(s) and contextual considerations, it should not be viewed as a viable substitute for field research. Regardless of the approach or approaches selected, it is crucial to enlist the necessary expertise to implement the methodology if it is not available in house.

Unfortunately, a single “gold standard” approach to measuring the unrecorded market is not feasible. Wherever possible, combining methodological approaches ― particularly when attempting to determine the size and composition of the unrecorded market ― is strongly encouraged, as the strengths of one approach may help compensate for the weaknesses of another. Moreover, to allow for greater comparability of findings, researchers should seek to use existing protocols for a given approach or approaches wherever possible. For example, looking to items that have already been implemented in numerous parts of the world is strongly recommended when carrying out a population survey (see Annex: Existing Survey Instruments).