Fewer than a quarter of 327 studies on informal food vendors define what 'informal' means

The 214 studies that gave policy advice are about 65 percent of the 327 analysed ^[12][18]. Counting how often they proposed water points or cold storage measures how far researchers agree ^[13]. Evidence of an effect on a vendor's income or a customer's diet would have to come from studies that measured those outcomes. The second of the review's three questions was how informality links to nutrition and food choice ^[5]. The write-up, provided to Phys.org by the Alliance of Bioversity International and CIAT, does not report those findings or how many studies measured diets ^[15].

At most 81 of the 327 studies said clearly who they were counting ^[17]. A vendor with a fixed stall and no licence is formal under a stall rule and informal under a licensing rule, so two studies of the same street can produce different counts of informal traders ^[6]. The write-up's headline scale figure is broad too. Its 1.23 billion is everyone employed in food systems worldwide, a majority of them informally ^[1]. That group is wider than the vendors the review studied.

Ramya Ambikapathi led the team, drawn from the Alliance, Cornell University, the Global Alliance for Improved Nutrition, Purdue University, the Kula Vyema Center of Food Economics and other institutions ^[14]. The authors argue that a definition steers policy. In their account, a location-based definition produces place-based policy, an infrastructure-based one produces market upgrades, and a licensing-based one produces formalisation drives ^[7]. Across the studies that made recommendations, the most consistent message was to drop the formal/informal binary and treat informality as a continuum ^[16].

The qualitative findings show why a binary fits badly. In Dhaka, researchers documented what they called 'quiet encroachment': male vendors ducked under tea tables when police approached, and their wives took over because officers were reluctant to arrest women ^[10]. The review files the ties that stabilise supply chains, share risk and lend legitimacy to unregistered work under the label 'social infrastructure' ^[11].

I think infrastructure is a sensible first bet, for a reason the tally does not capture. A water point or a cold-storage unit serves a vendor whether or not she holds a licence, so it does not have to wait for the field to agree on definitions. The view holds only if cities supply water and vending space without requiring a licence. A zone open only to registered vendors applies the licensing definition again.