publications

2021

1. Learning by (virtually) doing Experimentation and belief updating in smallholder agriculture

   Tjernström, Emilia, Lybbert, Travis J., Hernández, Rachel Frattarola, and Correa, Juan Sebastian

   Journal of Economic Behavior & Organization Sep 2021

   Abstract Cite

   In much of sub-Saharan Africa, soil quality heterogeneity hampers farmer learning about the returns to different inputs. This may help explain why relatively few farmers in the region use improved inputs. We study how Kenyan farmers respond to an interactive app that enables them to discover the returns to different inputs on a virtual farm that is calibrated to resemble their own. Farmers update both their beliefs and their behaviors after engaging with the virtual learning app. We measure beliefs by eliciting probability distributions and use an incentive-compatible experiment to measure behavior change. The experiment gave participants an input budget that they could allocate across farm inputs. After playing several virtual seasons on the app, they could update these allocations. Farmers revise their input allocations along several dimensions after the virtual learning experience. To support our interpretation that these adjustments stem from real learning, we show that farmers with the highest predicted returns to lime—an unfamiliar input in this region—increase their lime orders more than others. Our results suggest that engagement with a personalized virtual platform can induce real learning and enhance farmers’ beliefs and technology choices.

   @article{tjernstrom_learning_2021,
     bibtex_show = {true},
     title = {{Learning by (virtually) doing} {Experimentation} and belief updating in smallholder agriculture},
     volume = {189},
     issn = {0167-2681},
     shorttitle = {Learning by (virtually) doing},
     url = {https://www.sciencedirect.com/science/article/pii/S0167268121000901},
     doi = {10.1016/j.jebo.2021.03.001},
     language = {en},
     journal = {Journal of Economic Behavior \& Organization},
     author = {Tjernström, Emilia and Lybbert, Travis J. and Hernández, Rachel Frattarola and Correa, Juan Sebastian},
     month = sep,
     year = {2021},
     pages = {28--50},
     selected = {true}
   }

2019

1. Heterogeneous Impact Dynamics of a Rural Business Development Program in Nicaragua

   Carter, Michael R., Tjernström, Emilia, and Toledo, Patricia

   Journal of Development Economics May 2019

   Abstract Cite

   We study the impacts of a rural development program designed to boost the income of the small-farm sector in Nicaragua. Exploiting the random assignment of treatment, we find statistically and economically significant impacts on gross farm income and investment in productive farm capital. Using continuous treatment estimation techniques, we examine the evolution of program impacts over time and find that the estimated income increase persists and that the impacts on productive capital stock continue to rise even after the program concluded. Additionally, panel quantile methods reveal striking heterogeneity of program impacts on both income and investment. We show that this heterogeneity is not random and that there appear to exist low-performing household types who benefit little from the program, whereas high-performing (upper quantile) households benefit more substantially. Analysis using generalized random forests, a machine learning algorithm, points toward greater program impacts for households who were disadvantaged at baseline. Even after controlling for this source of heterogeneity, we find large and persistent differences in how much different types of households benefited from the program. While the benefit-cost ratio of the program is on average positive, the impact heterogeneity suggests that business development programs aiming to engage farm households as agricultural entrepreneurs have limitations as instruments to eliminate rural poverty.

   @article{carter_heterogeneous_2019,
     bibtex_show = {true},
     title = {Heterogeneous {Impact} {Dynamics} of a {Rural} {Business} {Development} {Program} in {Nicaragua}},
     volume = {138},
     issn = {0304-3878},
     url = {http://www.sciencedirect.com/science/article/pii/S0304387818304851},
     doi = {10.1016/j.jdeveco.2018.11.006},
     journal = {Journal of Development Economics},
     author = {Carter, Michael R. and Tjernström, Emilia and Toledo, Patricia},
     month = may,
     year = {2019},
     pages = {77--98}
   }

2. Money Matters‘:‘ The Role of Yields and Profits in Agricultural Technology Adoption

   Michler, Jeffrey D., Tjernström, Emilia, Verkaart, Simone, and Mausch, Kai

   American Journal of Agricultural Economics Apr 2019

   Abstract Cite

   Abstract. Despite the growing attention to technology adoption in the economics literature, knowledge gaps remain regarding why some valuable technologies are

   @article{michler_money_2019,
     bibtex_show = {true},
     title = {Money {Matters}`:` {The} {Role} of {Yields} and {Profits} in {Agricultural} {Technology} {Adoption}},
     volume = {101},
     copyright = {All rights reserved},
     issn = {0002-9092},
     url = {https://academic.oup.com/ajae/article/101/3/710/5057582},
     doi = {10.1093/ajae/aay050},
     language = {en},
     number = {3},
     journal = {American Journal of Agricultural Economics},
     author = {Michler, Jeffrey D. and Tjernström, Emilia and Verkaart, Simone and Mausch, Kai},
     month = apr,
     year = {2019},
     pages = {710--731}
   }

2018

1. Fitting and Interpreting Correlated Random Coefficient (CRC) Models Using Stata

   Barriga Cabanillas, Oscar, Michler, Jeffrey D., Michuda, Aleksandr, and Tjernström, Emilia

   Stata Journal Apr 2018

   Abstract Cite

   In this article, we introduce the community-contributed command randcoef, which fits the correlated random-effects and correlated random-coefficient models discussed in Suri (2011, Econometrica 79‘:‘ 159–209). While this approach has been around for a decade, its use has been limited by the computationally intensive nature of the estimation procedure that relies on the optimal minimum distance estimator. randcoef can accommodate up to five rounds of panel data and offers several options, including alternative weight matrices for estimation and inclusion of additional endogenous regressors. We also present postestimation analysis using sample data to facilitate understanding and interpretation of results

   @article{barriga_cabanillas_fitting_2018,
     bibtex_show = {true},
     title = {Fitting and {Interpreting} {Correlated} {Random} {Coefficient} ({CRC}) {Models} {Using} {Stata}},
     volume = {18},
     copyright = {All rights reserved},
     url = {https://www.lafollette.wisc.edu/sites/tjernstrom/randcoef_WP.pdf},
     number = {1},
     journal = {Stata Journal},
     author = {Barriga Cabanillas, Oscar and Michler, Jeffrey D. and Michuda, Aleksandr and Tjernström, Emilia},
     year = {2018},
     pages = {159--173}
   }

2. Natural Disasters, Social Protection, and Risk Perceptions

   Brown, Philip, Daigneault, Adam J., Tjernström, Emilia, and Zou, Wenbo

   World Development Apr 2018

   Cite

   @article{brown_natural_2018,
     bibtex_show = {true},
     title = {Natural {Disasters}, {Social} {Protection}, and {Risk} {Perceptions}},
     volume = {104},
     url = {https://www.sciencedirect.com/science/article/pii/S0305750X17303893},
     journal = {World Development},
     author = {Brown, Philip and Daigneault, Adam J. and Tjernström, Emilia and Zou, Wenbo},
     month = apr,
     year = {2018},
     pages = {310--325}
   }

2008

1. Do Differences in Attitudes Explain Differences in National Climate Change Policies?

   Tjernström, Emilia, and Tietenberg, Thomas H.

   Ecological Economics Apr 2008

   Cite

   @article{tjernstrom_differences_2008,
     bibtex_show = {true},
     title = {Do {Differences} in {Attitudes} {Explain} {Differences} in {National} {Climate} {Change} {Policies}?},
     volume = {65},
     copyright = {All rights reserved},
     number = {2},
     journal = {Ecological Economics},
     author = {Tjernström, Emilia and Tietenberg, Thomas H.},
     year = {2008},
     pages = {315--324},
     selected = {false}
   }

2017

1. Diverse Soils and Inputs Challenge Recommendations to Maize Farmers in Kenya

   Tjernström, Emilia, Carter, Michael, and Lybbert, Travis J.

   2017
2. Local Seed Company Fills a Niche to Increase Maize Productivity in Kenya

   Carter, Michael, Mathenge, Mary K., Bird, Sam, Lybbert, Travis J., Njagi, Timothy, and Tjernström, Emilia

   2017

2014

1. Spurring Technological Innovation and Poverty Reduction? Evaluating the Impact of a New Seed Market Actor in Kenya

   Carter, Michael R., Lybbert, Travis J., Mathenge, Mary K., and Tjernstrom, Emilia

   Mar 2014

2013

1. Identifying the Impact Dynamics of a Small Farmer Development Scheme in Nicaragua

   Tjernström, Emilia, Carter, Michael R., and Toledo, Patricia

   American Journal of Agricultural Economics, Papers and Proceedings Jul 2013

2012

1. Price Premiums for Organic Strawberries

   Carroll, Christine, Charlton, Diane, and Tjernström, Emilia

   Agricultural and Resource Economics Update Jul 2012

2008

1. Rational Foolishness Would Destroy a Public Service Broadcasting System

   Tjernström, Sune, and Tjernström, Emilia

   Journal of Media Economics Jul 2008

2009

1. Kunnigt och (o)kontroversiellt om råvarumarknaden (Book review of "Handbook of Primary Commodities in the Global Economy" by Marian Radetzki)

   Tjernström, Emilia

   Ekonomisk Debatt Jul 2009

   Cite

   @article{tjernstrom_kunnigt_2009,
     bibtex_show = {true},
     title = {Kunnigt och (o)kontroversiellt om råvarumarknaden ({Book} review of "{Handbook} of {Primary} {Commodities} in the {Global} {Economy}" by {Marian} {Radetzki})},
     volume = {37},
     number = {3},
     journal = {Ekonomisk Debatt},
     author = {Tjernström, Emilia},
     year = {2009},
     keywords = {book_review},
     pages = {85--88}
   }