VoxDev Development Economics

Between 1959 and 1961, between thirty and forty million people starved to death in China. The Great Famine had many causes, and one of them was a campaign to eradicate sparrows.
Shaoda Wang of the University of Chicago tells Tim Phillips about Mao Zedong's 1958 Four Pests Campaign, which led to the mass killing of sparrows, set off a chain of consequences that scientists had warned about, but political pressure had silenced. Sparrows eat crops, but they also eat the locusts and other insects that destroy the crops. Remove the sparrows and the pests go unchecked. Wang and his co-authors estimate the eradication cut national grain yields by 8-9%, accounting for roughly a fifth of the total agricultural decline during the famine.
The research behind this episode:
Frank, Eyal G., Qinyun Wang, Shaoda Wang, Xuebin Wang, and Yang You. 2024. "Campaigning for Extinction: Eradication of Sparrows and the Great Famine in China." NBER Working Paper 34087.
To cite this episode:
Phillips, Tim, and Shaoda Wang. 2025. "How killing sparrows contributed to the Great Chinese Famine.” VoxDev Talk (podcast). 

Assign this as extra listening. The citation above is formatted and ready for a reading list or VLE.

About Shaoda Wang

Shaoda Wang is an assistant professor at the Harris School of Public Policy, University of Chicago. His research spans environmental economics, political economy and development, with a focus on how state capacity and political incentives shape environmental and health outcomes in China and other developing countries.
Research cited in this episode

The Four Pests Campaign (1958). Launched as part of Mao Zedong's Great Leap Forward, the campaign targeted rats, flies, mosquitoes and sparrows. Sparrows were included on the grounds that they ate grain and reduced agricultural yields. Several prominent Chinese scientists warned at the time that removing sparrows would destabilise the food chain by eliminating a key predator of crop pests, particularly locusts. Their advice was ignored. The campaign resulted in the killing of an estimated two billion sparrows.
County gazetteers as a data source. Official harvest data reported by local governments to the central government during the Great Leap Forward was heavily inflated; local officials faced strong political incentives to overstate output, and those exaggerated figures contributed to the famine by masking food shortages from central planners. Wang and his co-authors instead use county gazetteers: records compiled by local elites through a bottom-up process with no link to the political reward structures that distorted official reporting. Comparison between the two sources reveals the scale of over-reporting in the official data.
Sparrow habitat suitability index. Rather than relying on reported sparrow kill counts, which were distorted by local officials seeking to demonstrate compliance with campaign targets, the paper constructs an index of how suitable each county's climate and ecological conditions are for sparrow habitation. Counties with high sparrow suitability were more exposed to the shock of eradication; comparing their crop yield and mortality trajectories against low-suitability counties before and after the campaign provides the causal identification strategy. The two groups followed similar trajectories before the campaign; divergence afterwards is attributed to the eradication.
State food procurement as a famine amplifier. The Great Famine was not simply a production shortfall. The central government continued to export food during the famine years because inflated harvest reports gave it no signal of the actual crisis. State procurement quotas extracted grain from rural communities at a time when households were already facing starvation; the political system that caused the sparrow eradication was also the mechanism that amplified its consequences.
More VoxDev Talks on this topic

The economics of ecosystems: How nature and economies interact. Eyal Frank of the University of Chicago — a co-author of the sparrows paper — on how to measure the economic value of biodiversity. His research on bats and white-nose syndrome, and on desert locusts, shows what happens when natural pest control collapses; the sparrows episode is the historical counterpart.
Related reading on VoxDev

The political economy of policy learning: Evidence from China, a VoxDev article on how misaligned incentives across China's political hierarchy distort policy experimentation and produce systematically exaggerated signals — the same dynamic that inflated both the sparrow kill counts and the harvest figures during the Great Leap Forward.
Autocratic rule and social capital: Evidence from Imperial China, a VoxDev article on the long-run effects of political persecution under autocratic rule in China, and how the suppression of dissent shapes economic and social behaviour across generations.
The economics of conservation in low- and middle-income countries, a VoxDev article surveying the evidence on maintaining natural ecosystems, the role of governance, and the costs of losing species whose economic value is not yet understood.

This is an episode from VoxDev's new podcast series, Ideas in Development. This series has a separate podcast feed, where you can find every episode of Oliver Hanney and Kurtis Lockhart's conversations on cities.
YouTube: https://www.youtube.com/watch?v=JKF3aJ96L2o 
Apple Podcasts: https://podcasts.apple.com/us/podcast/how-crime-takes-over-cities/id1866874059?i=1000763970538 
Spotify: https://open.spotify.com/episode/1YGI5Q0LDKRCSK8MHBHfEh?si=5EiiP-vbRnOYxoACBDbE0Q 
Audioboom: https://audioboom.com/posts/8895828-how-crime-takes-over-cities 
Substack: https://ideasindevelopment.substack.com/p/how-crime-captures-a-city 
VoxDev: https://voxdev.org/topic/institutions-political-economy/chris-blattman-how-crime-takes-over-cities 
How does organised crime take over a city – and can mayors act before it does?
Chris Blattman, economist and political scientist at the University of Chicago, joins the Ideas in Development cities series to explain how street gangs evolve into powerful criminal confederations, why cities like Medellín can have low homicide rates and still be almost completely captured, and what the "terrible trade-off" between violence, criminal power and political corruption means for policymakers.
We then discuss the perils faced by fast-growing African cities, where the conditions for organised crime to take root are quietly assembling.
Check out the Africa Urban Lab: https://www.aul.city/

Decades of agricultural development policy have chased yield. Bigger harvests, better seeds, more fertiliser. But how can we make farming more profitable? 
Craig McIntosh of UC San Diego is academic lead on a J-PAL Policy Insight covering twenty-three randomised evaluations of credit and grants for farmers in low- and middle-income countries. He tell Tim Phillips that although yields and revenues often rise, profit rarely responds in the same way. When farmers are already running their farms close to the margin, costs rise at the same rate as income, and the household bank balance does not move much. What can we bundle with credit to change that situation?
The research behind this episode:
Abdul Latif Jameel Poverty Action Lab (J-PAL). 2026. "Can relaxing credit constraints boost farmers' profits?” J-PAL Policy Insights. Last modified February 2026. Academic leads: Craig McIntosh and Tavneet Suri; insight authors: Leonie Rauls and Rebecca Toole.
To cite this episode:
Phillips, Tim, and Craig McIntosh. 2026. “Boosting farmers' profits?" VoxDev Talks (podcast). 

Assign this as extra listening. The citation above is formatted and ready for a reading list or VLE.

About the guest

Craig McIntosh is Professor of Economics at the School of Global Policy and Strategy, UC San Diego. His research spans development finance, agricultural credit, cash transfer design and the evaluation of large-scale anti-poverty interventions. 
Research cited in this episode

Microcredit take-up among farmers. Across four randomised evaluations of traditional microcredit aimed at farmers, in Morocco, Ethiopia, Bangladesh and Malawi, take-up sat between 13 and 33 percent. Standard microcredit repayment begins a week or two after disbursement, which is incompatible with a crop cycle that pays out cash once or twice a year. Group liability also breaks down in agriculture, where shocks like drought or floods hit borrowers together rather than one at a time.
Tailoring credit to the agricultural cycle. Restructured loans push take-up much higher. Nakano and Magezi in Tanzania allowed rice farmers to defer 80 percent of repayment until harvest; 39 percent borrowed and over 92 percent repaid. William Jack and co-authors in Kenya offered dairy farmers asset-collateralised loans for a water tank; take-up reached 44 percent against 2.4 percent for a typical joint-liability product. Lambon-Quayefio, Manjeer and Udry in Ghana offered digital credit with a three-month grace period; 59 percent of farmers took it up.
Sell low, buy high. Burke and co-authors in Kenya showed that smallholders routinely sell at the post-harvest price trough and buy back grain at hungry-season prices 20 to 40 percent higher. Harvest-time loans that allowed farmers to delay sales had take-up of 64 percent and produced returns around 29 percent for borrowers. Treated villages also saw flatter price trajectories, generating spillover benefits for non-borrowers.
Lean-season credit. Fink, Jack and Masiye in Zambia found that lean-season loans let farmers stop hiring out their labour and instead work their own land. Output rose by 9 percent. Loan repayments were comparable to the gain, leaving farmers roughly even on profits.
Selection into credit markets. Beaman, Karlan, Thuysbaert and Udry in Mali first offered loans, then offered grants to those who had refused. Returns to capital among would-be borrowers were on the order of 130 percent. Returns among those who had refused the loan were close to zero. Credit appears to self-target toward farmers who can use it productively, which is regressive in welfare terms and also exactly what a capital-scarce economy needs credit markets to do.
Input subsidy programmes (ISPs). Jayne and co-authors reviewed eighty studies of fertiliser subsidies across sub-Saharan Africa. Yields rise while subsidies are in place; profitability is mixed; targeting is frequently politically distorted, often skewed toward better-connected or wealthier farmers. The standout randomised exception is Carter, Laajaj and Yang in Mozambique, where two-thirds of recipients had never used fertiliser before; the programme produced sustained gains and a high benefit-cost ratio. By contrast, Gignoux and co-authors in Haiti found a fertiliser-voucher subsidy crowded out farmers' own input spending and lowered yields once the subsidy ended.
Cash transfers and diversification. In six studies measuring both farm and non-farm outcomes, three found households doubled down on agriculture and three saw movement into non-farm enterprises. The Zambian Child Grant evaluation by Handa and co-authors saw women invest in seeds, fertiliser and livestock and start non-farm businesses, with household income roughly doubling.
Bundled input programmes. Four randomised evaluations bundled credit or a grant with information, training or market access. All four lifted revenues; three of the four lifted incomes or profits. Harou and co-authors in Tanzania showed that fertiliser vouchers alone and soil testing alone did nothing; only the combination raised yields and revenues. Ashraf, Gine and Karlan's Kenya study on French-bean and baby-corn export found credit increased programme participation from 27 to 41 percent, even where it did not further raise income among participants.

In 2017, Argentina had the highest corporate income tax rate in Latin America. Reducing it was politically popular and economically desirable. Getting it through a Congress where the governing coalition held just 19% of Senate seats, while the fiscal deficit ran at close to 8% of GDP, was a harder problem. A package of reforms was planned, revenue-neutral and phased over five years: corporate tax on reinvested profits would fall from 35% to 25%; a minimum-wage deduction would reduce the payroll tax burden on firms employing informal workers; energy, alcohol, and sugar taxes would be reorganised on rational, emissions-based principles; and provincial governments would agree to phase out the cascading "ingresos brutos" sales tax in exchange for limits on public spending. 
In this week’s VoxDev Talk, Sebastian Galiani, who served as Deputy Minister of Economy in Argentina and led the design of the reform, tells Tim Phillips how the Macri government attempted to reform its tax structure, and what it teaches us about policy. Credibility, he says, was the biggest constraint: in a country as economically volatile as Argentina, what matters is not only what the law says, but whether investors believe it will survive a change of government.
The research behind this episode:
Afonso, Santiago, and Sebastian Galiani. 2025. "Motives and Constraints in the Implementation of Argentina's 2017 Tax Reform." NBER Working Paper 34442.
To cite this episode:
Phillips, Tim, and Sebastian Galiani. 2026. "Argentina's 2017 tax reform." VoxTalks Economics (podcast). 

Assign this as extra listening. The citation above is formatted and ready for a reading list or VLE.

About the guest

Sebastian Galiani is the Mancur Olson Professor of Economics at the University of Maryland. His research spanning political economy, public finance, and Latin American development has examined how institutions, property rights, and fiscal policy shape economic outcomes. He served as Deputy Minister of Economy in Argentina in 2017, where he led the design of the tax reform he examines in this episode.
Research cited in this episode

Ingresos brutos is a cascading sales tax levied by Argentina's provincial governments, applied each time a good changes hands along the supply chain. Unlike a value-added tax, it allows no deduction for taxes already paid at earlier stages; the burden compounds with the length of the production chain, making it particularly punishing for manufactured goods that pass through many hands. Galiani's team negotiated a deal under which the provinces agreed to phase this system out over five years and move toward a simpler, less distortive sales tax structure.
Second-best reform is the practice of improving a policy system as far as constraints allow rather than designing for the theoretically optimal outcome that cannot be achieved in practice. Galiani frames the 2017 reform explicitly in these terms: the design team mapped the distance between Argentina's actual tax system and optimal taxation, then asked how far they could move in that direction given the fiscal, political, and negotiating constraints they faced. The result departed from the ideal in every dimension; it was nonetheless a genuine improvement on what existed before.
Escape clauses are provisions written into legislation that suspend or modify specific commitments if defined trigger conditions are met. The 2017 reform included several: the inflation adjustment for the calculation of corporate assets, for example, would apply only if inflation continued to fall. Galiani describes escape clauses as essential when designing policy in high-volatility environments where external shocks are not exceptional events but a predictable feature of the landscape.
Related reading on VoxDev

How should economic researchers give policy advice? Stefan Dercon argues that giving second-best advice, taking into account what is politically achievable rather than what is theoretically optimal, often produces better outcomes than the standard model of advocating for the ideal and waiting.
How progressive taxation affects tax compliance in developing countries. Reforms that boost progressivity and are effectively communicated can yield higher compliance alongside greater fairness; evidence that the design and communication of a reform matter as much as its content.
Improving payroll-tax compliance through decentralised monitoring: Evidence from Mexico. Evidence that even formal firms evade payroll taxes, and that giving workers the right incentives to monitor their employers' wage reporting can substantially improve compliance; relevant context for Argentina's effort to reduce the payroll tax burden on unskilled workers.

At the start of every planting season, smallholder farmers needs seeds and fertiliser, but the income from the harvest that would pay for them is many months away. With no credit history and no collateral, banks aren’t going to give credit to farmers.They cope by selling livestock, pledging part of the harvest to a trader at a discount, or turning to neighbours.
Can we do a better job of lending to farmers? Monica Lambon-Quayefio of the University of Ghana tells Tim Phillips about a digital lending product for farmers in southern Ghana shows what this approach can do — but also where it still falls short. Working with Farmerline, a social enterprise that scores creditworthiness from farm and sales data rather than formal records, the trial randomly assigned eligible applicants to receive input loans worth around $40. Farm input expenditures rose by around 11%. But not profits. Find out why in this week’s episode.
The research behind this episode:
Karlan, Dean, Monica Lambon-Quayefio, Utsav Manjeer, and Christopher Udry. 2026. "Access to Digital Credit for Smallholder Farmers: Experimental Evidence from Ghana." Journal of Development Economics 181.
To cite this episode:
Phillips, Tim, and Monica Lambon-Quayefio. 2026. "Can digital credit unlock investment in smallholder farms?" VoxDev Talk 

Assign this as extra listening: the citation above is formatted and ready for a reading list or VLE.

About Monica Lambon-Quayefio

Monica Lambon-Quayefio is a senior lecturer in the Department of Economics at the University of Ghana, where her research focuses on social protection, agricultural technology, and experimental methods in development economics. The paper discussed in this episode is co-authored with Dean Karlan, Utsav Manjeer, and Christopher Udry, all of Northwestern University.
More VoxDev Talks on this topic

Mobile money in Ghana: Lessons for boosting financial inclusion: Tim Phillips speaks with Francis Annan about what Ghana's experience with mobile money reveals about reducing fraud and misconduct in rural financial systems, and what it takes for digital finance to reach the very poor.
What have we learned about microfinance?: What decades of research have established, where the evidence remains contested, and what the most important open questions are for policymakers thinking about expanding access to credit in low-income settings.
Related reading on VoxDev

The impact of digital credit in low-income countries: an overview of the evidence on how digital lending products affect borrowers, including the risks of overborrowing and the conditions under which short-term digital credit translates into improved economic outcomes.
How to boost digital banking adoption and savings in Ghana: evidence on what drives uptake of digital financial services among low-income households in Ghana, and what works when trying to shift behaviour away from informal savings arrangements.