Publication: Behaviorally Informed Messages Increase COVID-19 Vaccination Intentions: Insights from a Global Meta-Analysis
Loading...
Published
2024-11-22
ISSN
Date
2024-11-22
Author(s)
Pinzon Hernandez, Daniel Alejandro
Lim, Jungkyu Rhys
Dugas, Michelle
Moscoe, Ellen
Chatila, Mohamad
Cameron, Corey
Afif, Zeina
Orozco Olvera, Victor Hugo
Editor(s)
Abstract
During the COVID-19 pandemic, low- and middle-income countries struggled with lower vaccination rates compared to wealthier countries, posing challenges to reducing virus transmission, mitigating healthcare system pressures, and promoting economic recovery. Communications campaigns offer low-cost opportunities to overcome such challenges by strengthening vaccine confidence and intentions to get vaccinated, but empirical testing is needed to identify which messages will be most effective in different contexts. To support policy-making efforts to design effective communication rapidly during the pandemic, a global research program of 28 online experiments was conducted by recruiting respondents (123,270 individuals) through social media between January 2021 and June 2022 across 23 mostly low- and middle-income countries and territories. An individual participant data (IPD) meta-analysis of these data summarizes the results of this research program testing the impact of behaviorally informed messaging on vaccine intentions. Results from the meta-analysis show that among unvaccinated survey respondents, behaviorally informed messages significantly increased the odds of vaccination intention by 1.28 times overall and up to 1.93 times in individual studies (safety messages in Papua New Guinea). Significant pooled effects of specific framings ranged from increasing the odds of vaccination intention by 1.16 times (variant framing) to 1.45 times (experts and religious leaders framing). This research underscores the importance of communication tailored to address different drivers of vaccine hesitancy and offers insights for handling future health crises with behavioral communication strategies leveraging rapid insights afforded by social media.
Link to Data Set
Citation
“Pinzon Hernandez, Daniel Alejandro; Lim, Jungkyu Rhys; Dugas, Michelle; Moscoe, Ellen; Chatila, Mohamad; Cameron, Corey; Vakis, Renos; Afif, Zeina; Orozco Olvera, Victor Hugo. 2024. Behaviorally Informed Messages Increase COVID-19 Vaccination Intentions: Insights from a Global Meta-Analysis. Policy Research Working Paper; 10981. © World Bank. http://hdl.handle.net/10986/42455 License: CC BY 3.0 IGO.”
Digital Object Identifier
Associated URLs
Associated content
Other publications in this report series
Publication The Economic Value of Weather Forecasts: A Quantitative Systematic Literature Review(Washington, DC: World Bank, 2025-09-10)This study systematically reviews the literature that quantifies the economic benefits of weather observations and forecasts in four weather-dependent economic sectors: agriculture, energy, transport, and disaster-risk management. The review covers 175 peer-reviewed journal articles and 15 policy reports. Findings show that the literature is concentrated in high-income countries and most studies use theoretical models, followed by observational and then experimental research designs. Forecast horizons studied, meteorological variables and services, and monetization techniques vary markedly by sector. Estimated benefits even within specific subsectors span several orders of magnitude and broad uncertainty ranges. An econometric meta-analysis suggests that theoretical studies and studies in richer countries tend to report significantly larger values. Barriers that hinder value realization are identified on both the provider and user sides, with inadequate relevance, weak dissemination, and limited ability to act recurring across sectors. Policy reports rely heavily on back-of-the-envelope or recursive benefit-transfer estimates, rather than on the methods and results of the peer-reviewed literature, revealing a science-to-policy gap. These findings suggest substantial socioeconomic potential of hydrometeorological services around the world, but also knowledge gaps that require more valuation studies focusing on low- and middle-income countries, addressing provider- and user-side barriers and employing rigorous empirical valuation methods to complement and validate theoretical models.Publication The Macroeconomic Implications of Climate Change Impacts and Adaptation Options(Washington, DC: World Bank, 2025-05-29)Estimating the macroeconomic implications of climate change impacts and adaptation options is a topic of intense research. This paper presents a framework in the World Bank's macrostructural model to assess climate-related damages. This approach has been used in many Country Climate and Development Reports, a World Bank diagnostic that identifies priorities to ensure continued development in spite of climate change and climate policy objectives. The methodology captures a set of impact channels through which climate change affects the economy by (1) connecting a set of biophysical models to the macroeconomic model and (2) exploring a set of development and climate scenarios. The paper summarizes the results for five countries, highlighting the sources and magnitudes of their vulnerability --- with estimated gross domestic product losses in 2050 exceeding 10 percent of gross domestic product in some countries and scenarios, although only a small set of impact channels is included. The paper also presents estimates of the macroeconomic gains from sector-level adaptation interventions, considering their upfront costs and avoided climate impacts and finding significant net gross domestic product gains from adaptation opportunities identified in the Country Climate and Development Reports. Finally, the paper discusses the limits of current modeling approaches, and their complementarity with empirical approaches based on historical data series. The integrated modeling approach proposed in this paper can inform policymakers as they make proactive decisions on climate change adaptation and resilience.Publication Labor Demand in the Age of Generative AI: Early Evidence from the U.S. Job Posting Data(Washington, DC: World Bank, 2025-11-18)This paper examines the causal impact of generative artificial intelligence on U.S. labor demand using online job posting data. Exploiting ChatGPT’s release in November 2022 as an exogenous shock, the paper applies difference-in-differences and event study designs to estimate the job displacement effects of generative artificial intelligence. The identification strategy compares labor demand for occupations with high versus low artificial intelligence substitution vulnerability following ChatGPT’s launch, conditioning on similar generative artificial intelligence exposure levels to isolate substitution effects from complementary uses. The analysis uses 285 million job postings collected by Lightcast from the first quarter of 2018 to the second quarter of 2025Q2. The findings show that the number of postings for occupations with above-median artificial intelligence substitution scores fell by an average of 12 percent relative to those with below-median scores. The effect increased from 6 percent in the first year after the launch to 18 percent by the third year. Losses were particularly acute for entry-level positions that require neither advanced degrees (18 percent) nor extensive experience (20 percent), as well as those in administrative support (40 percent) and professional services (30 percent). Although generative artificial intelligence generates new occupations and enhances productivity, which may increase labor demand, early evidence suggests that some occupations may be less likely to be complemented by generative artificial intelligence than others.Publication The Lasting Effects of Working while in School(Washington, DC: World Bank, 2025-08-18)This paper provides the first experimental evidence on the long-term effects of work-study programs, leveraging a randomized lottery design from a national program in Uruguay. Participation leads to a persistent 11 percent increase in formal labor earnings, observable seven years after the program. Effects are stronger for youth who participate during pivotal educational transitions and are larger for vulnerable youth and men, while remaining positive for women and non-vulnerable youth. The program is highly cost-effective, with average impacts exceeding those of job training programs and comparable to early childhood investments.Publication It’s Not (Just) the Tariffs: Rethinking Non-Tariff Measures in a Fragmented Global Economy(Washington, DC: World Bank, 2025-10-22)As tariffs have declined, non-tariff measures (NTMs) have become central to trade policy, especially in high-income countries and regulated sectors like food and green technologies. Although NTMs may serve legitimate goals, they could also sort countries and firms into or out of markets based on compliance capacity and differences in product mix. Documenting recent advances in the estimation of ad valorem equivalents (AVEs), this paper uncovers new patterns of use and exposure of NTMs. High-income countries rely more heavily on NTMs relative to tariffs, while low- and middle-income countries face steeper AVEs on their exports. Firm-level evidence shows that NTMs disproportionately affect smaller firms, leading to market exit and concentration. Poorly designed NTMs can harm productivity and welfare, while coordinated, capacity-aware use can deliver inclusive outcomes. Policy design, transparency, and diagnostics must evolve to reflect the growing role—and risks—of NTMs in a fragmented global trade landscape.
Journal
Journal Volume
Journal Issue
Collections
Related items
Showing items related by metadata.
Publication Behavioral Science and COVID-19(Washington, DC: World Bank, 2022-07-27)The first Coronavirus (COVID-19) cases were reported in December 2019 (WHO, 2020). Governments around the world have tried various interventions to stop the COVID-19 spread and encourage vaccination. With growing evidence of the governments’ COVID-19 efforts to deal with the pandemic, this guide aims to summarize interventions and applications, and their effectiveness to address the following three COVID-19 topics: How to reduce COVID-19 spread; How to encourage people to get vaccinated; and How to address misinformation and fake news.Publication Find the Fake(Washington, DC: World Bank, 2024-09-30)The proliferation of misinformation and disinformation threatens to erode the credibility of public institutions and limit their capacity to implement policies that enhance public well-being. While health misinformation represents an urgent global challenge, relatively little research has examined solutions in low- and middle-income countries. This study experimentally tests the impact of a novel WhatsApp chatbot game pre-bunking inoculation intervention in Jordan to boost capacity to identify common misinformation techniques and reduce the likelihood of sharing misleading headlines with otherseffectively “inoculating” them against health misinformation. A sample of 2,851 participants was recruited online and randomly assigned to five study arms: (1) comprehensive game-based inoculation, (2) brief game-based inoculation that highlighted examples of only misinformation, (3) infographics-based inoculation, (4) exposure to placebo infographics unrelated to misinformation, and (5) pure control. To evaluate the impact of the intervention, the study assesses two main outcomes: (1) ability to discern accurately headlines using misinformation techniques and headlines that do not use misinformation techniques, and (2) discernment in sharing the two types of headlines. Compared to the placebo group, the comprehensive game significantly improved discernment of misinformation and reduced the likelihood of sharing misleading headlines. A brief version of the game yielded weaker effects on discernment of misinformation, but similarly reduced intentions to share misleading headlines. In contrast, exposure to infographics teaching similar techniques showed no significant impacts on discernment of misinformation, and marginal effects on intention to share misleading headlines. These findings suggest that games can effectively inoculate the public against misinformation in the context of a middle-income country in the short term. Future research is needed to explore the boundary conditions of the findings.Publication Can Environmental Cash Transfers Reduce Deforestation and Improve Social Outcomes? A Regression Discontinuity Analysis of Mexico’s National Program (2011-2014)(World Bank, Washington, DC, 2019-01)Environmental conditional cash transfers, or "payments for ecosystem services" are a centerpiece of global efforts to protect biodiversity, safeguard watersheds, and mitigate climate change by reducing forest loss. This paper evaluates the impacts of Mexico's national payments for ecosystem services program, which provides five years of payments to landowners in exchange for maintaining and managing natural land cover. Using a regression discontinuity design, the paper studies impacts on environmental, socioeconomic, and social capital outcomes for the 2011-14 program cohorts. The analysis finds that treated communities increased management activities to protect land cover, such as patrolling for illegal conversion or combatting soil erosion (by 48 percent compared to controls). The program reduced the loss of tree cover in areas at high risk of deforestation (by 29 percent compared to controls), with effects being larger for those that have been in the program the longest (38 percent compared to controls). These results are similar to estimates of impact for earlier program cohorts and continue to highlight the importance of targeting the program to areas of high risk of land cover loss to increase environmental effectiveness. The program continued to reach poor communities and households, but estimated impacts on household wealth indicators are small in magnitude and not statistically significant. These results indicate that community-level conditional payments did not harm household-level socioeconomic indicators, a key safeguard requirement of conservation policies of the United Nations Programme on Reducing Emissions from Deforestation and Forest Degradation. The data also show that payments for ecosystem services significantly increased community social capital -- the institutions, attitudes, and values that govern human interactions -- (by 9 percent compared to controls), and these externally provided incentives did not crowd out household contributions to other community work.Publication The Entertaining Way to Behavioral Change(World Bank, Washington, DC, 2019-09)This paper tests the effectiveness of an entertainment education television series, MTV Shuga, aimed at providing information and changing attitudes and behaviors related to HIV/AIDS. Using a simple model, the paper shows that “edutainment” can work through an individual or a social channel. This study is a randomized controlled trial conducted in urban Nigeria, where young viewers were exposed to MTV Shuga or a placebo television series. Among those exposed to MTV Shuga, the trial created additional variation in the social messages they received and the people with whom they watched the show. The study finds significant improvements in knowledge and attitudes toward HIV and risky sexual behavior. Treated subjects are twice as likely to get tested for HIV eight months after the intervention. The study also finds reductions in sexually transmitted diseases among women. These effects are stronger for viewers who reported being more involved with the narrative, consistent with the psychological underpinnings of edutainment. The trial’s experimental manipulations of the social norm component did not produce significantly different results from the main treatment. The individual effect of edutainment thus seems to have prevailed in the context of this study.Publication Behavioral insights for COVID-19 vaccine uptake in the Caribbean(World Bank, Washington, DC, 2023-10-18)In the wake of the pandemic, the greatest obstacle to COVID-19 vaccination in the Caribbean is vaccine acceptance and uptake rather than supply. Social media surveys were conducted in three Caribbean countries to better understand the socio-behavioral drivers of vaccine acceptance and uptake to address ongoing vaccination challenges to prevent morbidity and mortality. Behavioral science made critical contributions to global COVID-19 vaccination campaigns. We wanted to understand vaccine intentions, behavioral biases and barriers limiting vaccine uptake to better target vaccination efforts and inform health communication campaigns. Surveys were administered via Facebook messenger chatbot, with data drawn from a non-probability sample of both vaccinated and unvaccinated respondents. Surveys were conducted in April-May 2022, with respondents from Belize (n=2,657), Jamaica (n=4,096), and Haiti (n=10,419). We focused on the ‘movable middle’, i.e., people who are still undecided about whether they wanted the COVID-19 vaccine. Further, surveys tested the impact of different behaviorally informed messages on vaccine intention. Each country presented unique vaccination uptake challenges which required specific interventions or outreach strategies to change vaccination attitudes and behaviors. The responses of the movable middle provide insights into how this group could be targeted for improving uptake. Knowledge of this group can aid in targeting messaging, selection of trusted messengers and channels.
Users also downloaded
Showing related downloaded files
Publication The Container Port Performance Index 2023(Washington, DC: World Bank, 2024-07-18)The Container Port Performance Index (CPPI) measures the time container ships spend in port, making it an important point of reference for stakeholders in the global economy. These stakeholders include port authorities and operators, national governments, supranational organizations, development agencies, and other public and private players in trade and logistics. The index highlights where vessel time in container ports could be improved. Streamlining these processes would benefit all parties involved, including shipping lines, national governments, and consumers. This fourth edition of the CPPI relies on data from 405 container ports with at least 24 container ship port calls in the calendar year 2023. As in earlier editions of the CPPI, the ranking employs two different methodological approaches: an administrative (technical) approach and a statistical approach (using matrix factorization). Combining these two approaches ensures that the overall ranking of container ports reflects actual port performance as closely as possible while also being statistically robust. The CPPI methodology assesses the sequential steps of a container ship port call. ‘Total port hours’ refers to the total time elapsed from the moment a ship arrives at the port until the vessel leaves the berth after completing its cargo operations. The CPPI uses time as an indicator because time is very important to shipping lines, ports, and the entire logistics chain. However, time, as captured by the CPPI, is not the only way to measure port efficiency, so it does not tell the entire story of a port’s performance. Factors that can influence the time vessels spend in ports can be location-specific and under the port’s control (endogenous) or external and beyond the control of the port (exogenous). The CPPI measures time spent in container ports, strictly based on quantitative data only, which do not reveal the underlying factors or root causes of extended port times. A detailed port-specific diagnostic would be required to assess the contribution of underlying factors to the time a vessel spends in port. A very low ranking or a significant change in ranking may warrant special attention, for which the World Bank generally recommends a detailed diagnostic.Publication Global Economic Prospects, January 2025(Washington, DC: World Bank, 2025-01-16)Global growth is expected to hold steady at 2.7 percent in 2025-26. However, the global economy appears to be settling at a low growth rate that will be insufficient to foster sustained economic development—with the possibility of further headwinds from heightened policy uncertainty and adverse trade policy shifts, geopolitical tensions, persistent inflation, and climate-related natural disasters. Against this backdrop, emerging market and developing economies are set to enter the second quarter of the twenty-first century with per capita incomes on a trajectory that implies substantially slower catch-up toward advanced-economy living standards than they previously experienced. Without course corrections, most low-income countries are unlikely to graduate to middle-income status by the middle of the century. Policy action at both global and national levels is needed to foster a more favorable external environment, enhance macroeconomic stability, reduce structural constraints, address the effects of climate change, and thus accelerate long-term growth and development.Publication The Container Port Performance Index 2020 to 2024: Trends and Lessons Learned(Washington, DC: World Bank, 2025-09-22)The Container Port Performance Index (CPPI) provides a global benchmark of how container ports perform in handling vessel calls. Developed jointly by the World Bank and S&P Global Market Intelligence, it measures the time ships spend in port and relates this to the number of containers moved during that time. This approach makes the CPPI a unique diagnostic tool that can highlight patterns in port operations and shed light on global and regional supply chain dynamics. Now in its fifth edition, the CPPI report covers the period from 2020 to 2024. It builds on a well-established methodology to generate scores for more than 400 container ports worldwide. Over time, the CPPI has become a trusted reference point for policymakers, industry stakeholders, and researchers who seek to understand how ports adapt to shocks, recover from disruptions, and identify opportunities for investments, reform and modernization. A major innovation in this edition is the introduction of multi-year trend analysis. Rather than presenting annual snapshots, the report now tracks how CPPI scores have changed across five years. This longitudinal perspective reveals shifts in port performance, showing where scores have risen, fallen, or remained stable. By linking these movements to external factors, the CPPI offers insights into how global and regional supply chains evolve under pressure. The results clearly mirror the crises that have shaken global trade. During the COVID-19 pandemic, CPPI scores in different regions declined sharply as congestion, equipment shortages, and delays overwhelmed many ports. By 2023, global averages rebounded in parallel with easing freight markets and reduced congestion. Yet 2024 brought new challenges: the Red Sea crisis disrupted major trade lanes, while climate-related constraints at the Panama Canal added further stress. These shocks were reflected in lower global and several regional average scores, underscoring the vulnerability of maritime transport to geopolitical and environmental events. The CPPI is not about comparing one port against another, but about understanding changes in performance over time. Ports that improved their scores often did so by reducing time at anchor, optimizing berth operations, investing in digital tools, and strengthening coordination across logistics partners. The evidence confirms that improvements are possible across ports of all sizes, and that rising scores are linked to deliberate actions to minimize time in port relative to containers moved. By consolidating five years of results, this edition transforms the CPPI into a long-term reference point. It shows how global crises have affected shipping, how different regions have adapted, and what lessons can be drawn for future resilience. The World Bank and S&P Global Market Intelligence remain committed to maintaining the CPPI as a global public good, providing transparency, comparability, and practical insights to support more reliable and sustainable maritime supply chains.Publication Global Economic Prospects, June 2025(Washington, DC: World Bank, 2025-06-10)The global economy is facing another substantial headwind, emanating largely from an increase in trade tensions and heightened global policy uncertainty. For emerging market and developing economies (EMDEs), the ability to boost job creation and reduce extreme poverty has declined. Key downside risks include a further escalation of trade barriers and continued policy uncertainty. These challenges are exacerbated by subdued foreign direct investment into EMDEs. Global cooperation is needed to restore a more stable international trade environment and scale up support for vulnerable countries grappling with conflict, debt burdens, and climate change. Domestic policy action is also critical to contain inflation risks and strengthen fiscal resilience. To accelerate job creation and long-term growth, structural reforms must focus on raising institutional quality, attracting private investment, and strengthening human capital and labor markets. Countries in fragile and conflict situations face daunting development challenges that will require tailored domestic policy reforms and well-coordinated multilateral support.Publication Digital Progress and Trends Report 2023(Washington, DC: World Bank, 2024-03-05)Digitalization is the transformational opportunity of our time. The digital sector has become a powerhouse of innovation, economic growth, and job creation. Value added in the IT services sector grew at 8 percent annually during 2000–22, nearly twice as fast as the global economy. Employment growth in IT services reached 7 percent annually, six times higher than total employment growth. The diffusion and adoption of digital technologies are just as critical as their invention. Digital uptake has accelerated since the COVID-19 pandemic, with 1.5 billion new internet users added from 2018 to 2022. The share of firms investing in digital solutions around the world has more than doubled from 2020 to 2022. Low-income countries, vulnerable populations, and small firms, however, have been falling behind, while transformative digital innovations such as artificial intelligence (AI) have been accelerating in higher-income countries. Although more than 90 percent of the population in high-income countries was online in 2022, only one in four people in low-income countries used the internet, and the speed of their connection was typically only a small fraction of that in wealthier countries. As businesses in technologically advanced countries integrate generative AI into their products and services, less than half of the businesses in many low- and middle-income countries have an internet connection. The growing digital divide is exacerbating the poverty and productivity gaps between richer and poorer economies. The Digital Progress and Trends Report series will track global digitalization progress and highlight policy trends, debates, and implications for low- and middle-income countries. The series adds to the global efforts to study the progress and trends of digitalization in two main ways: · By compiling, curating, and analyzing data from diverse sources to present a comprehensive picture of digitalization in low- and middle-income countries, including in-depth analyses on understudied topics. · By developing insights on policy opportunities, challenges, and debates and reflecting the perspectives of various stakeholders and the World Bank’s operational experiences. This report, the first in the series, aims to inform evidence-based policy making and motivate action among internal and external audiences and stakeholders. The report will bring global attention to high-performing countries that have valuable experience to share as well as to areas where efforts will need to be redoubled.