Using crowd-sourced data for real-time monitoring of food prices during the COVID-19 pandemic: Insights from a pilot project in northern Nigeria

AI-imputed and crowdsourced price data show strong agreement with traditional price surveys in data-scarce environments

Continuous access to up-to-date food price data is crucial for monitoring food security and responding swiftly to emerging risks. However, in many food-insecure countries, price data is often delayed, lacks spatial detail, or is unavailable during crises when markets may become inaccessible, and rising prices can rapidly exacerbate hunger. Recent innovations, such as AI-driven data imputation and crowdsourcing, present new opportunities to generate continuous, localized price data. This paper evaluates the reliability of these approaches by comparing them to traditional enumerator-led data collection in northern Nigeria, a region affected by conflict, food insecurity, and data scarcity. The analysis examines crowdsourced prices for two staple food commodities, maize and rice, submitted daily by volunteers through a smartphone application over 36 months (2019-2021), and compares them with data collected concurrently by trained enumerators during the final eight months of 2021. Additionally, the crowdsourced dataset is compared to AI-imputed prices from the World Bank's Real-Time Prices (RTP) database. Data from the alternative methods reflected similar price inflation trends during the COVID-19 pandemic. Pearson's correlation coefficients indicate strong statistical agreement between crowdsourced and enumerator-collected prices (r =  0.94 for yellow and white maize, r =  0.96 for Indian rice, and r =  0.78 for Thailand rice). Furthermore, the crowdsourced data shows a high correlation with the AI-imputed prices (r =  0.99 for maize, and r =  0.94 for rice). The results from additional statistical tests of normality and paired means shows that the discrepancies between price datasets are consistent with measurement error rather than differences in actual price dynamics. Further tests of equivalence confirmed that enumerator and crowdsourced prices represent the same underlying market processes for specific commodity subtypes, and connotes that crowdsourced price data is a credible reference for validating AI-imputed estimates. The results support the use of AI imputation and crowdsourcing methods to improve price data collection and track market dynamics in near real time. These data innovations can be particularly valuable in areas that are underrepresented in national aggregate data due to limited monitoring capacity, and where high-frequency local data can aid targeted interventions.

Spatial Price Transmission and Dynamic Volatility Spillovers in the Global Grain Markets: A TVP-VAR-Connectedness Approach

The global food market's escalating volatility has led to a complex network of uncertainty and risk transmission across different grain markets. This study utilizes the Time-Varying Parameter Vector Autoregression (TVP-VAR)-Connectedness approach to analyze the price transmission and volatility dynamics of key grains, including wheat, maize, rice, barley, peanut, soybean, and soybean meal, and their dynamic spillover directions, intensity, and network. By integrating the TVP-VAR-Connectedness model, this research captures the time-varying variability and interconnected nature of global grain price movements. The main findings reveal significant spillover effects, particularly in corn prices, with prices of soybean dominating other grains while prices of peanut and corn experience higher external spillover effects from other grains. The conclusions drawn underscore the imperative for policymakers to consider a holistic perspective of all types of grains when addressing global food security, with this study providing valuable insights for risk management in the grain sector at both global level and country level.

Food Retail Resilience Pre-, during, and Post-COVID-19: A Bibliometric Analysis and Research Agenda

This paper aims to conduct a bibliometric mapping and systematic review of the food retail industry's resilience strategy in the context of COVID-19. Specifically, we aim to identify relevant research gaps in the industry during the pre-, during, and post-pandemic periods and highlight the differences between B2B and B2C sectors. We analyzed articles in the Scopus database from 2019 to 2022 using the PRISMA method for article selection, resulting in a total of 69 articles. We employed a VOS viewer for bibliometric mapping. Our analysis revealed that most studies focused on the impact of COVID-19, with only a few examining the pre- and post-pandemic periods critically. In the B2C context, we identified two major topics: changes in purchasing and consumption behavior, and food waste and safety. In the B2B sector, the two most recurrent subjects were retailers' strategies and supply chain management. This study provides valuable insights for policymakers by exploring industry trends and for scholars by highlighting future research agendas based on the identified topics.

Citizen science approaches to crowdsourcing food environment data: A scoping review of the literature

Globally, the adoption and implementation of policies to improve the healthiness of food environments and prevent population weight gain have been inadequate. This is partly because of the complexity associated with monitoring dynamic food environments. Crowdsourcing is a citizen science approach that can increase the extent and nature of food environment data collection by engaging citizens as sensors or volunteered computing experts. There has been no literature synthesis to guide the application of crowdsourcing to food environment monitoring. We systematically conducted a scoping review to address this gap. Forty-two articles met our eligibility criteria. Photovoice techniques were the most employed methodological approaches (n = 25 studies), commonly used to understand overall access to healthy food. A small number of studies made purpose-built apps to collect price or nutritional composition data and were scaled to receive large amounts of data points. Twenty-nine studies crowdsourced food environment data by engaging priority populations (e.g., households receiving low incomes). There is growing potential to develop scalable crowdsourcing platforms to understand food environments through the eyes of everyday people. Such crowdsourced data may improve public and policy engagement with equitable food policy actions.

Resilience, endogenous policy responses to COVID-19, and their impacts on farm performance

Policy measures aimed at containing the spread of the COVID-19 pandemic had unintended consequences on economic activities globally. In this study, we isolate and investigate the short-term partial impacts of six such measures on the farm and nonfarm incomes of agricultural households and examine the related resilience factors. Using Nigeria as a case study, we find that the COVID containment measures had mixed effects on farm and non-farm incomes in the short run. These varying effects are due to households' resilience and vulnerability factors, including land size, wealth, income diversification, involvement in processing activities, and reliance on hired labor. Our findings highlight the need for more targeted health crisis containment measures which consider the uniqueness, diversity, and regional heterogeneity of agriculture, especially the potential implications for farm viability.

From mobile crowdsourcing to crowd-trusted food price in Nigeria: statistical pre-processing and post-sampling

Timely and reliable monitoring of food market prices at high spatial and temporal resolution is essential to understanding market and food security developments and supporting timely policy and decision-making. Mostly, decisions rely on price expectations, which are updated with new information releases. Therefore, increasing the availability and timeliness of price information has become a national and international priority. We present two new datasets in which mobile app-based crowdsourced daily price observations, voluntarily submitted by self-selected participants, are validated in real-time within spatio-temporal markets (pre-processed data). Then, they are reweighted weekly using their geo-location to resemble a formal sample design and allow for more reliable statistical inference (post-sampled data). Using real-time data collected in Nigeria, we assess the accuracy and propose that our reweighted estimates are more accurate with respect to the unweighted version. Results have important implications for governments, food chain actors, researchers and other organisations.

COVID-19 mobility restrictions and stay-at-home behaviour in 2020 were associated with higher retail food prices worldwide

COVID-19 policy responses have included mobility restrictions, and many people have chosen to stay at home to avoid exposure. These actions have ambiguous impacts on food prices, lowering demand for food away from home and perishables, while increasing supply costs for items where workers are most affected by the pandemic. We use evidence from 160 countries to identify the net direction and magnitude of association between countries' real cost of all food and mobility restriction stringency. We investigate the deviation of each month's price level in 2020 from that month's average price level during the previous three years and find that an increase in mobility restriction stringency from no restrictions to most restrictive is associated with an increase in the real cost of all food of more than one percentage point across all models. We then examine the relationship between retail food price levels by food group and stay-at-home behaviour around markets in 36 countries and find positive associations for non-perishables, dairy and eggs.

Contemporary Approaches for Monitoring Food Marketing to Children to Progress Policy Actions

PURPOSE OF REVIEW

Protecting children from unhealthful food marketing is a global priority policy for improving population diets. Monitoring the nature and extent of children's exposure to this marketing is critical in policy development and implementation. This review summarises contemporary approaches to monitor the nature and extent of food marketing to support policy reform.

RECENT FINDINGS

Monitoring approaches vary depending on the stage of progress of related policy implementation, with resource implications and opportunity costs. Considerations include priority media/settings. marketing techniques assessed, approach to classifying foods, study design and if exposure assessments are based on media content analyses or are estimated or observed based on children's media use. Current evidence is largely limited to high-income countries and focuses on content analyses of TV advertising. Ongoing efforts are needed to support monitoring in low-resource settings and to progress monitoring to better capture children's actual exposures across media and settings.

COVID-19 outbreak and rural household food security in the Western Democratic Republic of the Congo

Although global assessments of the initial impacts of the coronavirus disease (COVID-19) have focused on income, jobs, and health conditions, this study constitutes one of the first studies that assessed the impact of COVID-19 on food security in DRC and established the short-term implications of the COVID-19 outbreak on rural households' food security in DRC. In addition, the study recommendations contributed to shaping government interventions toward the pandemic in the Country. The study used data from four western provinces of the country on 1339 households. Our results show that 80 % of households experienced an increase in food prices, 61 % a noticeable decrease in the availability of food, and 54 % a decrease in their dietary diversity. Due to changes in food availability, dietary diversity, and food accessibility imposed by the COVID-19 outbreak, >70 % of households experienced either a decrease in the consumption of meat, milk, fish, and cereals or an increase in their consumption of traditional vegetables. In addition, COVID-19 significantly affected food security dimensions in larger households, households with a greater number of members aged 35 years and above, households headed by women, households where members participate in associations or cooperatives, households that depend on crop sales as the major source of income, and in poorer households. These findings highlight the significant implications of the COVID-19 outbreak on household food security in western DRC and underscore the need for emergency interventions to strengthen the resilience of rural people and accelerate their recovery and other long-term measures toward sustainable and inclusive development.

COVID-19 Pandemic-Induced Disruptions and Implications for National Food Security and Farm Incomes: Farm-Level Evidence from Indian Punjab

By using the data from a primary survey of 1100 farm households from Indian Punjab, the present study examined the impact of COVID-19 pandemic-induced disruptions on food security and farm incomes. The paddy-wheat-based production system showed resilience to the challenges of the COVID-19 situation. Farmers adapted effectively to the changed equilibrium and there was no decline in food production, land lease activity or cropping patterns. The disruptions in agricultural machinery services and input supplies led to a rise in the rent of machinery and input prices. Agricultural wages also jumped due to scarcity of agricultural labour. The study highlights no imminent threat to food supplies from Punjab and hence to national food security. It showed that farmers may need some financial support to counter the effect of rising costs of farming. There is a need to enhance the resilience of various input and output markets in agriculture in the future.

Perceived effects of COVID-19 restrictions on smallholder farmers: Evidence from seven lower- and middle-income countries

CONTEXT

The COVID-19 pandemic caused unprecedented global disruption and continues to wreak havoc. Dire predictions were made about the risks to smallholder farmers in lower- and middle- income, but hard data have been lacking. We present the results from 9201 interviews with smallholder farmers from seven countries.

OBJECTIVE

The objectives are to describe: i) how farmers perceive the key effects of the COVID-19 pandemic and containment measures on livelihoods and food security; ii) the effects on agricultural activities; iii) the coping strategies households deployed.

METHODS

Household surveys were conducted as part of ongoing monitoring programs during the latter half of 2020. Sites in seven countries were covered: Burundi; Kenya; Rwanda; Tanzania; Uganda; Zambia; and Vietnam. Findings are representative of smallholder farmers across multiple districts per country.

RESULTS AND CONCLUSIONS

The effects of the COVID-19 containment measures were widespread and often perceived to be severe. Food purchase, off-farm income, sale of farm produce, and access to crop inputs were all affected. In locations under more stringent restrictions during the time of the survey, up to 80% of households had to reduce food consumption and/or variety. Almost all households with off-farm incomes reported reductions, by half on average. A half to three-quarters of households (depending on the location) with income from farm sales reported losses compared to the pre-pandemic situation. In locations with more relaxed containment measures in place during the time of the survey, less frequent and less severe economic and food security outcomes were perceived by the respondent, with around 20% of households reporting negative outcomes. Mobility restrictions, reduced market access, crashes in sale price for agricultural goods, and soaring prices for food purchase were key factors. Sale prices generally dropped for all agricultural products in any given location, and affected not only high-value perishable products, but also staple crops such as maize and cassava. Depending on the location, between 30% and 90% of the households applied coping strategies in response to the pandemic during 2020. There was an almost complete absence of official aid amongst households interviewed.

SIGNIFICANCE

Our results raise the thorny issue of how best to balance containment of disease against the wellbeing of the vulnerable rural population in lower- and middle-income countries. There is a risk that the buffering capacity of rural people will become exhausted. Possible policy measures to limit negative outcomes include i) tiered mobility restrictions with travel allowed for economic reasons; ii) short-term price guarantee schemes to stabilise the food system; iii) direct aid; iv) the timely re-installation of distribution channels for agricultural inputs.

Consumer experiences of food environments during the Covid-19 pandemic: Global insights from a rapid online survey of individuals from 119 countries

This study investigates consumer experiences of food environments and food acquisition practices during the Covid-19 pandemic. Our rapid assessment online survey featured a convenience sample of 2015 individuals from 119 countries, spanning Western Europe, North America, Latin America, Asia-Pacific, and Africa. Data collection took place in April 2020 during the second month of the pandemic. Participants were recruited via existing networks of the United Nations System Standing Committee on Nutrition, through social media, and by snowballing. The majority of participants were female (71.9%), from low- and middle-income countries (51.0%), and working in nutrition or healthcare (39.3%). Qualitative thematic analysis and descriptive statistics reveal a series of common global experiences related to food availability and accessibility, food prices and affordability, food acquisition practices, and food preparation and consumption. The importance of community food participation, food sharing, and resource allocation are highlighted, along with increasing awareness of healthy diets and food waste. We identify ten synergistic policy entry points to: 1) build resilient and equitable food environments resistant to stresses and shocks; 2) harness positive dietary-related behaviors manifested during the pandemic; and, 3) mitigate the projected nutrition crisis and promote sustainable healthy diets for all.

Leveraging Digital Tools and Crowdsourcing Approaches to Generate High-Frequency Data for Diet Quality Monitoring at Population Scale in Rwanda

Diet quality is a critical determinant of human health and increasingly serves as a key indicator for food system sustainability. However, data on diets are limited, scattered, often project-dependent, and current data collection systems do not support high-frequency or consistent data flows. We piloted in Rwanda a data collection system, powered by the principles of citizen science, to acquire high frequency data on diets. The system was deployed through an unstructured supplementary service data platform, where respondents were invited to answer questions regarding their dietary intake. By combining micro-incentives with a normative nudge, 9,726 responses have been crowdsourced over 8 weeks of data collection. The cost per respondent was < $1 (system set-up, maintenance, and a small payment to respondents), with interactions taking <15 min. Exploratory analyses show that >70% of respondents consume tubers and starchy vegetables, leafy vegetables, fruits, legumes, and wholegrains. Women consumed better quality diets than male respondents, revealing a sex-based disparity in diet quality. Similarly, younger respondents (age ≤ 24 years) consumed the lowest quality diets, which may pose significant risks to their health and mental well-being. Middle-income Rwandans were identified to have consumed the highest quality diets. Long-term tracking of diet quality metrics could help flag populations and locations with high probabilities of nutrition insecurity, in turn guiding relevant interventions to mitigate associated health and social risks.

Affordability of Healthy and Sustainable Diets in Nigeria

This study examines the cost and affordability of healthy diets in Nigeria. Using the 2015/16 and 2018/19 waves of Nigeria General Household Surveys, we find that, generally, the least-cost options to meet dietary recommendations for vegetables, dairy, and protein-rich foods are more expensive to meet than that of other food groups. Despite improvements during the survey years, the challenges of affordability of healthy diets appear more pronounced in rural than urban, among poorest household groups, and in northern than southern Nigeria. Results suggest that it will be more expensive to meet the dietary recommendation for dairy foods if priority will be given for food systems sustainability over concerns for food preferences of the households. It will however be cheaper to achieve dietary recommendations for vegetables, fruits and starchy staples even when households give more consideration to food systems sustainability than tastes and preferences in their choice of healthy foods. Relative affordability of protein-rich foods are less affected by whether (or not) tastes/preferences or food systems sustainability drives healthy food choices. Key implication is that interventions targeting on affordability of healthy diets should give greater attention to the poorest of the poor, to rural than urban, and to northern than southern Nigeria. Implications relevant for research, policy, and other actors that focus on transformation of the food systems toward achieving healthier diets in a sustainable food systems are discussed.