A scoping review of market links between value chain actors and small-scale producers in developing regions

The past two decades have seen rapid growth in developing regions, with urbanization, diet diversification and the expansion of food supply chains creating substantial market opportunities for farmers and employment across supply-chain segments. The midstream actors—processors, wholesalers, logistics firms—comprise a large share of the food system and serve as farmers’ proximate link to markets, yet are often underrepresented in policy debates. Existing research has largely focused on formal contracts between large firms and farmers, despite the fact that only a small share of smallholders sell under such contracts. This review asks whether and how much value chain actors provide resources and services to farmers outside formal contracts, and whether such non-contract interactions improve smallholders’ welfare. Focusing primarily on SMEs due to the exclusion of formal contracts, the study assesses farm-level outcomes and the mechanisms driving them. A key contribution is documenting that SMEs in non-contract relations frequently provide complementary services similar to those seen in formal contract schemes, with implications for inclusive growth and SDG 2.

Research on transforming food systems has emphasized contract farming and resource provision by large processors and supermarkets. Classic tied credit-output literature portrayed SME traders as potentially exploitative through interlinked credit and output markets. More recent work highlights the rise of the ‘hidden middle’ and its potential role in upgrading smallholders. However, evidence on non-contract interactions and their welfare impacts has been limited, with gaps in livestock sectors and in assessing primary welfare outcomes alongside intermediate outcomes. The literature also shows a mismatch between policy rhetoric on gender and environmental sustainability and empirical studies, which rarely incorporate these dimensions. This review synthesizes post-2000 evidence across Africa, Asia and Latin America to fill these gaps by focusing on SMEs’ non-contract linkages with smallholders and associated outcomes.

Design: Protocol-driven scoping review following PRISMA-ScR guidance, pre-registered on the Open Science Framework. Five steps included articulating the research question, comprehensive searches, study selection using predefined criteria, data extraction and charting, and synthesis. Search strategy: Multiple databases searched (CAB Abstracts, Web of Science Core Collection, Scopus, EconLit, ProQuest Dissertations & Theses Global, Africa Theses and Dissertations, AgEcon Search) plus 15+ grey literature sources via custom web-scraping. Expert consultation and prior knowledge added further studies. After deduplication, 12,320 records remained from 18,207 total. Screening: A machine-learning model added metadata fields (populations, geographies, interventions, outcomes) to accelerate initial title screening. Records were screened in Covidence by two independent reviewers at title/abstract and full-text stages; conflicts resolved by a third reviewer. PRISMA flow: 12,320 after duplicates; 3,822 post title screening; 849 full texts assessed; 202 studies included. Exclusions at full text (n=647) due to wrong intervention (230), study design (115), outcomes (126), language (55), insufficient link information (27), methodology (34), population (12), time frame (5), geography (1), and unavailable full text (42). Inclusion criteria: Post-2000, English language; low- or middle-income countries in Africa, Asia or Latin America; explicit links involving physical and/or monetary exchange between small-scale producers and midstream/downstream value chain actors (traders, processors, logistics, input suppliers in the midstream); experimental or observational designs (including qualitative); and measurement of at least one farm-level outcome (income, poverty, food security; technology/practice adoption; commercialization; yield/productivity; price level/variability). Credit-only interventions, government/NGO programs supplying free/subsidized goods/services, certification, and formal contract farming were excluded. Data extraction and quality appraisal: One or more authors extracted bibliographic details, study design, sample size, producer characteristics, focal actors and interactions, outcomes and effects, and whether gender, environment or climate change were addressed. A general methodological assessment rated methodology description and justification as high, medium or low quality. Data were summarized by emerging themes to inform policy recommendations. Outcome categories were coded as primary (income, poverty, food security), intermediary (yield/productivity, price), and secondary (technology/practice adoption, commercialization). 241 focal actor cases were identified across 202 studies, yielding 555 coded outcomes.

- Publication characteristics: 73% peer-reviewed journal articles; 10% grey literature working papers; 7% conference papers; 5% book chapters; 5% theses/dissertations. Most studies were rated high quality; 15.5% of quantitative and 20% of qualitative studies were low quality due to insufficient methodological detail. - Temporal and geographic distribution: Over 40% published in the last 4 years and over 80% in the last 10 years. Settings: 49% Africa, 33% Asia, 21% Latin America. - Sectoral focus: 77% crop production, 18% livestock, remainder mixed. High-value crops featured in 55% vs 39% staple crops, revealing gaps in livestock and staple crop coverage. - Gender and environment: Only 12% of studies included a gender focus and 9% examined environmentally sound practices, highlighting a disconnect with policy priorities. - Prevalence and role of SMEs: Excluding formal contracts yielded a sample dominated by SMEs: small enterprises comprised 75% of trader cases and nearly 90% of processor cases. SMEs frequently provided complementary services beyond core trading/processing/logistics functions. - Complementary services by output buyers (Table 1): Among trader/processor/cooperative/supermarket/other modern/government buyers, the share of links with services included: arrange transport 12/19/9/11/19/0%; provide credit 22/31/14/7/19/0%; provide inputs 16/25/30/7/38/0%; provide extension 12/19/35/7/25/0%; purchase agreements 25/19/18/50/31/50%. Warehousing: traders 4%, processors 13%, supermarkets 4%. - Other modern channels: Inputs 38%, extension 25%, credit 19%, purchase agreements 31%, transport 19%. - Input suppliers and logistics (Extended Data Table 1): Cooperatives as input providers offered extension in >40% of interactions and purchased output in 25%. Other input suppliers provided extension in 31%; logistics providers offered extension in 33%, purchased output in 44%, and warehousing in 33% of their interactions. - By product type (Extended Data Table 2): For buyers/processors, assistance rates among staple/high-value/livestock farmers included purchase agreements 22/34/32%, inputs 15/16/32%, credit 9/14/23%, arrange transport 8/11/11%, warehousing 6/2/4%. - Outcomes overall: 83% of focal actor cases showed at least one positive outcome for farmers; by actor type: buyers/processors 81%, input suppliers 96%, logistics 100% (n=9). By region: Asia 87%, Africa 86%, Latin America 76%. By production: livestock 87% vs crops 83%; staples 88% vs high-value crops 83% (Table 2). - Outcomes by category (Extended Data Table 3): Positive effects in 78% of primary outcomes (income/poverty/food security), 67% of intermediary outcomes (yield/price), and 84% of secondary outcomes (technology/practice adoption), totaling 77% positive across all outcomes (N=555 outcome records). - Link characteristics and impacts (Table 3): Positive outcomes were more common when buyers provided complementary services: arrange transport (12% of positive vs 8% of negative/inconclusive outcomes), credit (19% vs 13%), inputs (24% vs 18%), and extension (20% vs 13%). For input suppliers, positive cases more often involved also purchasing output (8% vs 0%). Differences in outcomes were not driven by informal purchase agreements alone (similar prevalence in positive vs negative cases: 37% vs 39%). - Facilitators of positive outcomes: 65% of studies citing enabling conditions highlighted complementary services; most frequent were capacity building/extension (23%), credit (16%), multi-stakeholder platforms (14%), and market information (12%). Infrastructure availability (irrigation, transport, processing, storage, communications) was noted in 23% and conducive policies/regulation in 18%. - Challenges associated with negative outcomes: Reported inhibitors included capacity constraints of cooperatives/traders, low trust and information asymmetries, high transaction costs (risks of side-selling and product rejection), non-inclusiveness especially for marginalized producers, financial constraints limiting pre-harvest services, and buyer market power. Benefits tended to be greater for men than women where gender was analyzed.

The review directly addresses whether non-contract interactions with midstream and downstream value chain actors benefit small-scale producers. The synthesis shows that SMEs routinely provide complementary services—credit, inputs, training, logistics—that mitigate market failures and asset constraints, enabling technology adoption, productivity gains, better prices, and ultimately improved incomes and food security. These results reframe SMEs not as mere intermediaries but as pivotal enablers of inclusive market participation, particularly where formal contracts are rare. The preponderance of positive outcomes across geographies and product types underscores the potential of SME-led arrangements to support SDG 2. At the same time, the scarcity of gender- and environment-focused analyses limits understanding of differential benefits and sustainability pathways. Enabling infrastructure and supportive policy environments amplify positive effects, while capacity, trust, and transaction cost challenges can undermine outcomes, pointing to areas where public action can catalyze more effective SME–farmer linkages.

This scoping review of 202 studies demonstrates that, in the absence of formal contracts, SMEs in the midstream and downstream of agri-food value chains frequently provide complementary services that facilitate smallholders’ adoption of technologies and practices, improve productivity and prices, and enhance welfare. Non-contract interactions with traders, processors, cooperatives, and logistics providers yield positive outcomes in most cases and across outcome categories, supporting SDG 2 objectives. Policy should recognize SMEs as allies in delivering rural services and reduce constraints to their operation. Recommended actions include incentivizing SMEs to extend complementary services to remote and underserved producers; expanding SME access to finance; promoting environmentally beneficial practice adoption; cutting red tape; improving transport, energy, and communications infrastructure; and lowering digital connectivity costs. Future research should deepen evidence on livestock value chains, systematically assess gender-differentiated impacts, and evaluate how SME platforms can drive environmentally sustainable practices.

- Language and time-frame constraints: Only English-language studies published in or after 2000 were included, which may omit relevant evidence from other languages or earlier periods. - Scope exclusions: Formal contract farming, certification schemes, and government/NGO programs with free or subsidized inputs/services were excluded; findings do not generalize to those interventions. - Evidence gaps: Limited number of livestock-focused studies and few studies concurrently assessing primary and intermediate outcomes constrain comprehensive welfare inference. Gender and environmental sustainability were rarely addressed (12% and 9% of studies, respectively). - Limited observations for some actor types: Few logistics provider cases (n≈9 for outcomes) reduce statistical confidence for that category. - Methodological variability: Although most studies were rated of high quality, some lacked methodological detail; scoping reviews synthesize breadth rather than provide causal estimates, which may limit causal attribution.