Research

Published and Forthcoming Papers

The Effects of Independent Local Radio on Tanzanian Public Opinion: Evidence from a Planned Natural Experiment (Journal of Politics, 2023) replication materials | project website | pre-analysis plan | blog


We describe a natural experiment occasioned by an abrupt increase in the transmission range of an independent Tanzanian radio station whose broadcasts emphasize current affairs and gender equality. Some villages that formerly lay outside the catchment area of this radio station could now receive it, while nearby villages remained outside of reception range. Prior to the change in transmitter range in 2018, we conducted a baseline survey in both treated and untreated villages and found them to be similar in terms of prevailing social attitudes and political interest. An endline survey conducted in 2020 shows that respondents in areas that received the new radio signal were substantially more likely to listen to the station, and their levels of political interest and knowledge about domestic politics were significantly higher than their counterparts in villages where the signal could not reach. Attitude change on a range of gender issues, however, was sporadic.

Donald P. Green, Dylan W. Groves, Constantine Manda, Beatrice Montano, and Bardia Rahmani


Perspective Taking Through Partisan Eyes: Cross-National Empathy, Partisanship, and Attitudes Towards International Cooperation  (Journal of Politics, 2023)  pre-analysis plan | paper | replication materials | blog


How does cross-national empathy influence public attitudes towards international cooperation? Few studies have considered whether the capacity to see the world from the perspective of other actors promotes international cooperation or how partisanship may condition empathy’s influence. In this paper, we argue that cross-national empathy increases support for international agreements because seeing issues through the eyes of other states expands the range of considerations that individuals use in forming their attitudes. However, partisan attachments undercut this effect. Across three waves of an original survey experiment covering 6,292 respondents, we find that cues to “step into” the perspective of other states modestly increase aggregate support for international cooperation. But this effect is concentrated entirely among those with weak partisan attachments, regardless of the issue area (climate change or nuclear nonproliferation) and potential partner country (China or India). Our results speak to both the promises and shortcomings of empathy as a device for encouraging cooperative outcomes in international affairs.

Don Casler and Dylan W. Groves 


Understanding Journalism Impact: A Multidimensional Taxonomy for Professional, Organizational, and Societal Change  (Journal of Applied Journalism and Media Studies, 2023) paper | coverage

How should we measure the impact of investigative journalism? Media scholars and practitioners have turned their attention towards understanding the causal effect of media reports on a range of social, political, and economic outcomes. Their interest has been spurred by the increased availability of data, by the emergence of new tools for rigorously assessing causal effects, and by pressure from donors interested in understanding the returns on their investments in media and journalism programs. Drawing on literature from multiple disciplines, we propose a multi-faceted metric which future researchers, journalists and news agencies will be able to use when analyzing media impact.

Anya Schiffrin, Andre Correa-Almeida, Lindsay Green-Barber, Adelina Yankova, Dylan W. Groves 


Seeing Cattle like a State: Sedentist Assumptions of the Namibian Livestock Identification and Traceability System (Nomadic Peoples, 2023) paper | coverage


Livestock identification and traceability systems (LITS) are an increasingly prominent component of national livestock development policies around the world. In theory, LITS allow governments to more efficiently track and respond to disease and livestock theft. However, this paper argues that LITS are suffused with sedentist assumptions that are at odds with the livestock management practices of pastoralist communities. Drawing on qualitative interviews as well as one author’s experience of growing up and managing cattle in a pastoralist community, we review the sedentist assumptions that animate the Namibian Livestock Identification and Traceability System (NamLITS). We then describe how pastoralists in north-western Namibia perceive that NamLITS has affected their economic, social and political lives, as well as the strategies that pastoralists use to comply and circumvent NamLITS. We conclude with lessons for governments and development practitioners that are considering implementing livestock tracing systems as well as mobile communities affected by them.

Max Mauerman, Venoo Tjiseua, Dylan W. Groves (author order randomized)


A Radio Drama’s Effects on Attitudes Toward Early and Forced Marriage: Results from a Field Experiment in Rural Tanzania (Comparative Political Studies, 2022)  pre-analysis plan | paper | replication materials | project website


Early and forced marriage (EFM) is an increasing focus of international organizations and local non-government organizations. This study assesses the extent to which attitudes and norms related to EFM can be changed by locally tailored media campaigns. A two-hour radio drama set in rural Tanzania was presented to Tanzanian villagers as part of a placebo controlled experiment randomized at the village level. A random sample of 1,200 villagers was interviewed at baseline and invited to a presentation of the radio drama, 83% of whom attended. 95% of baseline respondents were reinterviewed two weeks later, and 97% fifteen months after that. The radio drama produced sizable and statistically significant effects on attitudes and perceived norms concerning forced marriage, which was the focus of the radio drama, as well as more general attitudes about gender equality. Fifteen months later, treatment effects diminished, but we continue to see evidence of EFM-related attitude change. 

Donald P. Green, Dylan W. Groves, Constantine Manda, Beatrice Montano, and Bardia Rahmani


Community-based Rangeland Management in Namibia Improves Resource Governance but not Environmental and Economic Outcomes (Nature - Communications Earth & Environment, 2022) pre-analysis plan | paper | replication materials | project website | coverage 1 | coverage 2


Classic theories suggest that common pool resources are subject to overexploitation. Community-based resource management approaches may ameliorate tragedy of the commons effects. Here we use a randomized evaluation in Namibia’s communal rangelands to study a comprehensive four-year program to support community-based rangeland and cattle management. We find that the program led to persistent and large improvements for eight of thirteen indices of social and behavioral outcomes. Effects on rangeland health, cattle productivity and household economics, however, were either negative or nil. Positive impacts on community resource management may have been offset by communities’ inability to control grazing by non-participating herds and inhibited by an unresponsive rangeland sub-system. This juxtaposition, in which measurable improvements in community resource management did not translate into better outcomes for households or rangeland health, demonstrates the fragility of the causal pathway from program implementation to intended socioeconomic and environmental outcomes. It also points to challenges for improving climate change–adaptation strategies. 

(* denotes equal authorship): D. Layne Coppock*, Lucas Crowley, Susan L. Durham, Dylan W. Groves*, Julian C. Jamison*, Dean Karlan*, Brien E. Norton, R. Douglas Ramsey 


A Radio Drama’s Effects on HIV Attitudes and Policy Priorities: A Field Experiment in Tanzania (Health Education and Behavior, May 2021) pre-analysis plan | paper | replication materials


A growing body of evidence investigates how entertainment education influences knowledge about HIV, stigma toward those with HIV, and openness to disclosing one’s HIV status. The present study shows that in addition to these effects, mass media interventions may influence audiences’ policy priorities, such as their demand for local access to HIV/AIDS medical care. A condensed (2 hours) version of a popular Swahili radio drama was presented to rural Tanzanians as part of a placebo-controlled experiment, clustered at the village level. A random sample comprising 1,200 participants were interviewed at baseline and invited to attend a presentation of the radio drama, and 83% attended. Baseline respondents were reinterviewed 2 weeks later with a response rate of 95%. In addition to increasing listeners’ knowledge and support for disclosure of HIV status, the radio drama produced sizable and statistically significant effects on listeners’ preference for hypothetical candidates promising improved HIV/AIDS treatment. 

Donald P.  Green, Dylan W. Groves, and Constantine Manda


The Mismeasurement of Cattle Ownership in Namibia's Northern Communal Areas (Nomadic Peoples, 2020) paper


The standard approach to measuring livestock ownership in pastoralist communities relies on an assumption of uniformity that does not reflect the diverse concepts of ownership held by pastoralists themselves. In Namibia's Koakaveld Region, Himba and Herero pastoralist communities have a rich vocabulary for categorising the origins, usage rights and cultural valence of their cattle. Drawing on both authors' experience overseeing a large-scale rangeland management programme evaluation in Namibia's Northern Communal Areas – and one author's experience growing up in and keeping cattle in a Himba pastoralist community – we show how the standard approach to measuring cattle ownership undermines accurate estimates of livestock wealth, off-take and inequality, and obfuscates pastoralist's strategies for turning ecological variability to their advantage. We conclude with lessons about how multi-dimensional data collection methods improve upon the standard approach to livestock ownership measurements. 

Dylan W. Groves and Venoo Tjiseua (author order randomized)


The Influence of Two Levels of Debushing in Namibia's Thornbush Savanna on Overall Soil Fertility, Measured Through Bioassays (Namibian Journal of the Environment, 2017)


A healthy and productive rangeland depends on well-functioning ecosystem services such as effective cycling of water and nutrients. After rangeland has degraded, bushes may encroach in nature's attempt to restore water and nutrient cycling. When bush encroachment is addressed by debushing, with harvested bush wood sold off the land, then nutrient cycling is disrupted and soil fertility is likely to decline. Former debushing activities on different parts of farms of the Cheetah Conservation Fund in central Namibia provided the opportunity to assess the influence of debushing on overall fertility of soil. Sites were selected on the farm representing nine examples of each of uncleared, partially cleared and totally cleared land. The debushing had taken place at different times, varying between two and 13 years previously. Soil was collected from each of these 27 sites and subjected to bioassay by growing barley (Hordeum vulgare) and Moringa oleifera. Seedling emergence and height at five weeks for both species were greatest in uncleared soil and lowest in totally cleared soil, indicating the loss of soil fertility as debushing intensifies. There was no evidence of restoration of soil fertility, even 13 years after debushing. Nutritious grass is unlikely to grow well after debushing, and more bush is likely to regrow in nature's attempt at restoring fertility over the long term. If faster restoration is sought, then the full spectrum of minerals removed in harvested wood should be replaced on the land.

Ibo Zimmermann, Mattis Nghikembua, D Shipingana, Dylan W. Groves, T Aron, L Marker


Working Papers

Governments Respond to Watchdog Journalism: Evidence from a Field Experiment in Tanzania  paper | pre-analysis plan | coverage


I evaluate the influence of investigative journalism on government responsiveness using a national-scale randomized controlled trial in Tanzania. I collaborated with 15 regional radio stations to identify 206 communities experiencing service delivery problems like flooded roads, broken water points, and missing medical supplies. I then randomly assigned half the communities to the treatment group and half the communities to a pure control condition. In treatment communities, journalists investigated the service delivery problem, broadcast their findings on regional radio, and conducted follow up reports several months later. Seven months after the reports were broadcast, independent auditors evaluated the service delivery problem in all 206 communities. I find that treatment communities received higher audit scores on average (coefficient = 0.25 standard deviations, randomization inference p-value = 0.033), amounting to one road or water point repair in every four treated communities. The investigations generated observable responses by un-elected government ministries but not citizens, local government officials, or members of parliament.

Dylan W. Groves


Information or Motivation? Why Governments Respond to Watchdog Journalism paper | pre-analysis plan


I evaluate two mechanisms by which journalism influences village government responsiveness: informing government officials about the preferences of their constituents and motivating officials with the threat of public exposure. I first draw on surveys of 4,200 citizens and 340 leaders across 109 Tanzanian villages to document whether leaders understand, share, and respond to the policy preferences of their constituents. I then examine the effect of two overlapping treatments, each designed to capture a mechanism of journalism's influence. In the ``information'' experiment, I randomly assigned leaders to receive information about the priorities of their constituents. In the ``motivation'' experiment, I randomly assigned leaders to be contacted by journalists planning reports on a specific development issue in the leader's village. To evaluate outcomes, I developed a behavioral measure of the willingness of village leaders to lobby district council officials for development projects on behalf of their constituents. I find mixed evidence for the role of information, strong evidence for the role of motivation, and no evidence for complimentary between the two mechanisms. The effect is concentrated among elected officials rather than bureaucrats, but not in electorally competitive communities.

Dylan W.  Groves


The Supply of Watchdog Journalism in Tanzania


I analyze the supply of local journalism in Tanzania. I combine three original data sets: a comprehensive history of radio station ownership in Tanzania, a national survey of local journalists in Tanzania, and a hand-coded data set of every news story published by local radio stations in Tanzania over a five month period. I show that despite a rapid rise in the number of local and independent media stations in Tanzania and a journalistic culture that is generally supportive of ``watchdog journalism,'' the slant of local news coverage in Tanzania remains overwhelmingly pro-government. The most dramatic bias occurs at stations owned by the government and stations owned by individuals with significant business interests outside the radio station, while the bias at radio stations controlled by individuals affiliated with the ruling party is surprisingly muted. Media market competition is also associated with reduced pro-government bias.

Dylan W.  Groves


The Effects of Mass Media on Political and Social Attitudes: Evidence from a Radio Distribution Experiment in Tanzania


For nearly a century, scholars have studied the ways in which exposure to mass communication influences social and political attitudes. Although experimental studies abound, they primarily focus on how exposure to a particular program or channel affects what audiences think; rarely have experiments randomly provided the means to consume a particular type of mass media. The present study reports the results of two experiments in rural Tanzania in which survey respondents were randomly assigned to receive radios and were reinterviewed approximately 15-20 months later.  Although the treatment group, as expected, became much more likely to listen to radio than the control group, the downstream effects on political and social attitudes are mixed. We find no appreciable effects on political participation or interest in politics, but we do see gains in knowledge about current events and increased concern about crime.  Attitudes about gender equality tend to move in the more progressive direction, and those who received radios also tend to become more accepting of stigmatized groups.  Those in the treatment group came to rate the ruling party more favorably, perhaps reflecting the political capture of nominally independent radio stations in the region, but these effects are not large and do not apply to ratings of the current president.

Donald P. Green, Dylan W. Groves, Beatrice Montano, and Bardia Rahmani 


Narrative Entertainment Shapes Policy Priorities: Evidence from Four Field Experiments in Tanzania (under review)


A growing body of work finds that entertainment-education interventions can influence attitudes, beliefs, and behaviors, but few studies consider their effects on audiences' policy priorities. We present results from a series of experiments conducted in Tanzania that estimate the impact of four radio dramas on audiences' prioritization of environmental protection, countering gender-based violence, reducing early and forced marriage, and improving access to HIV treatment. Interviewing listeners weeks after they were exposed to the drama, we measure their policy priorities in two ways.  First, we use a conjoint experiment to assess listeners' propensity to vote for hypothetical candidates running on different policy platforms, some of which coincide with the theme of the audio drama.  Second, we present listeners with a small set of cards, each of which represents a possible village goal (or problem), and invite them to sort the cards in order of their importance.  Three of the four dramas significantly increased listeners’ preference for hypothetical candidates promising to address the issue featured in the drama, and all four dramas elevated the perception that the issue represents a top priority for the community. Pooling across studies (N = 4,464), the average treatment effects of narrative messages on voting and prioritization are substantial and statistically significant. We use machine learning methods to investigate whether people with various background attributes -- age, education, gender, religion, and exposure to mass media -- respond differently to the dramas. Perhaps surprisingly, we find sizable effects of similar magnitude across an array of different respondent profiles. The results suggest that, like news from credible sources, narrative entertainment can influence which issues audiences take to be important. 

Salma Emmanuel, Donald P. Green, Dylan W. Groves,  Constantine Manda, Beatrice Montano, Bardia Rahmani


Assessing the Impact of the ICIJ Pandora Papers Investigation (under review) coverage


The question of how to measure and quantify the impact of investigative reporting has long bedeviled communications scholars, journalists and media development practitioners. This paper utilizes a recently introduced taxonomy of journalism impact to analyze the impact of one of the largest collaborations of investigative journalism ever conducted: the International Consortium of Investigative Journalists’ (ICIJ) Pandora Papers. Drawing on a new global survey of more than 55 media outlets that participated in the consortium, our analysis yields both substantive and methodological insights. Substantively, we show that collaborative investigations generate substantial positive “internal” returns for participating organizations, such as professional development and new media partnerships, although we observe no evidence of increased revenue. Notably, there is a large multiplier effect as the partner organizations contribute time and resources to the collaborations with ICIJ. Methodologically, we show the value of organizing studies of media impact using a multi-dimensional taxonomy and propose several amendments to ensure that the full range of media impacts are captured.

Anya Schiffrin, Audrey Hatfield,  Lindsay Green-Barber, Dylan W. Groves


The Persuasive Power of Supreme Courts: Evidence from Tanzania


Do constitutional court rulings shape social attitudes and perceived social norms? Rigorous evidence from outside of industrialized democracies is scarce. This paper evaluates the influence of a recent ruling by Tanzania's supreme court which held that laws permitting marriage for girls under the age of 18 are unconstitutional. We randomly assigned 1,950 respondents in rural Tanzania to hear a radio report about the ruling or to a control condition. Respondents who heard the report were 8 percentage points more likely to reject all forms of early marriage and 5.4 percentage points more likely to say they would report early marriage to authorities. However hearing the report did not influence perceptions of community norms or willingness to speak out against early marriage, and the persuasive effect of the report was attenuated when presented alongside a countervailing signal from Tanzania's Attorney General. 

Salma Emmanuel, Dylan W. Groves, Constantine Manda, Donald P. Green, Beatrice Montano, Bardia Rahmani


Religious Elite Messaging and Women's Political Participation


Can religious leaders use their standing to promote women's political participation (WPP) in the developing world? We present the results of a survey experiment conducted in northeastern Tanzania that estimates the effect of a pro-WPP audio message from a progressive religious elite on behavioral intentions, attitudes, and norms relating to female office-seeking. Across two studies, we find that the progressive religious elite's message makes villagers more likely on average to say they would encourage their daughter or niece to run for political office. These effects on behavioral intentions persisted a month later. Moreover, we find suggestive evidence that the children of respondents who received the progressive elite's message became more interested in running for political office. By contrast, we find muted or inconsistent effects of the progressive message on attitudes and norms, and of conservative messages on all three outcomes. The results suggest that interventions that leverage local religious elites can effectively reduce familial gatekeeping of women's political participation in socially conservative communities.

Bardia Rahmani, Dylan W. Groves, Beatrice Montano, and Francis Ngatigwa


A Radio Drama's Effects on Environmental Protection: Experimental Evidence from Tanzania


We report the results of an experiment conducted in rural Tanzania in which 1,360 respondents from 34 villages were randomly assigned to attend a screening of one of two radio dramas. The treatment drama depicts a corrupt bargain between a business developer and a public official to sell off the natural resources of a fishing village; the hero of the story rallies villagers to reject the deal in favor of environmental preservation. A placebo drama focused on an unrelated topic. Outcomes were assessed through a survey conducted four weeks later with 98.5\% of original participants. Participants who were randomly exposed to the treatment drama became more knowledgeable about climate change, more likely to cite environmental protection as a political priority, and substantially more supportive of pro-environmental policies and candidates. No effects were found on other outcomes, such as respondents’ proclivity to engage in or punish illegal logging.

Bardia Rahmani, Dylan W. Groves, Beatrice Montano, and Donald P. Green, Beatrice Montano


A Radio Drama's Effects on Gender Based Violence: Experimental Evidence from Tanzania


Can edutainment sensitize listeners to the problem of gender-based violence (GBV) and build support for a collective response? While a robust literature focuses on the incidence of intimate partner violence in Sub-Saharan Africa, few studies consider the broader range of threats that women experience in public settings, such as harassment, sexual assault, and sexual violence. We study how edutainment shapes awareness, policy priorities, and preferred responses to these aspects of GBV through a placebo-controlled experiment randomized at the village level in rural Tanzania. A random sample of 1,250 villagers was interviewed at baseline and invited to one of two randomly assigned radio drama screenings, then interviewed again one month later.  The 90-minute radio drama that focuses on GBV both raises awareness about the risks women face in their daily lives and increases the importance that audiences accord to sexual violence as a community problem. Narrative mass media offers an effective and scalable means for spurring collective action responses to threats to women's safety in public spaces.

Beatrice Montano, Salma Emmanuel, Donald P. Green, Dylan W. Groves, Bardia Rahmani


Works in Progress

A National-Scale Field Experiment on Radio Messaging and Family Planning in Nigeria

with John Marshall, Belinda Archebong, and Margaret McConnell (Intervention ongoing)


A National-Scale Field Experiment of Radio Messages and Public Health Services in Tanzania

with Salma Emmanuel, Constantine Manda, and John Marshall (Intervention ongoing)


Bias and Precision in Measurement of Livestock Weight

with Andrew Dillon, Alexander Fertig, and Dean Karlan


Household and Community Spillover Effects of Persuasive Messaging: Experimental Evidence from Tanzania 

with Donald P. Green, Beatrice Montano, and Bardia Rahmani (Analysis complete)


Policy Papers

Journalism for development: the role of journalism promoting democracy and political accountability and sustainable development paper | coverage 1  | coverage 2 | coverage 3

Joseph E. Stiglitz, Anya Schiffrin, and Dylan W. Groves


Improving Rangeland and Livestock Management in Namibia paper | coverage 1 | coverage 2

D. Layne Coppock*, Lucas Crowley, Susan L. Durham, Dylan W. Groves*, Julian C. Jamison*, Dean Karlan*, Brien E. Norton, R. Douglas Ramsey