Sweeping the flies away: evidence from a fruit fly eradication program

2020 ◽  
Vol 47 (5) ◽  
pp. 1920-1962
Author(s):  
Lina Salazar ◽  
Julian Aramburu ◽  
Marcos Agurto ◽  
Alessandro Maffioli ◽  
Jossie Fahsbender

Abstract This article evaluates the short-term impacts of a fruit fly integrated pest management program in Peru. Exploiting arbitrary variation in the program’s intervention borders, we use a geographical regression discontinuity design to identify the program’s effects on agricultural outcomes. Pre-treatment balance tests show that producer and farm-level pre-treatment characteristics evolve smoothly at the intervention border. Results indicate that farmers within treated areas improved pest knowledge and are more likely to implement prevention and control practices. Also, they increased fruit production and sales. Our findings are confirmed by placebo tests and are robust to alternative regression discontinuity bandwidths and polynomials.

2011 ◽  
Vol 19 (4) ◽  
pp. 385-408 ◽  
Author(s):  
Devin Caughey ◽  
Jasjeet S. Sekhon

Following David Lee's pioneering work, numerous scholars have applied the regression discontinuity (RD) design to popular elections. Contrary to the assumptions of RD, however, we show that bare winners and bare losers in U.S. House elections (1942–2008) differ markedly on pretreatment covariates. Bare winners possess largeex antefinancial, experience, and incumbency advantages over their opponents and are usually the candidates predicted to win byCongressional Quarterly's pre-election ratings. Covariate imbalance actually worsens in the closest House elections. National partisan tides help explain these patterns. Previous works have missed this imbalance because they rely excessively on model-based extrapolation. We present evidence suggesting that sorting in close House elections is due mainly to activities on or before Election Day rather than postelection recounts or other manipulation. The sorting is so strong that it is impossible to achieve covariate balance between matched treated and control observations, making covariate adjustment a dubious enterprise. Although RD is problematic for postwar House elections, this example does highlight the design's advantages over alternatives: RD's assumptions are clear and weaker than model-based alternatives, and their implications are empirically testable.


ILR Review ◽  
2020 ◽  
Vol 73 (5) ◽  
pp. 1095-1118
Author(s):  
Matthias Umkehrer ◽  
Philipp vom Berge

The authors evaluate the exemption of long-term unemployed job seekers from Germany’s national minimum wage. Using linked survey and administrative micro data, they rely on a regression discontinuity design to identify the effects of the policy by comparing hiring rates, employment stability, and entry wages around the administrative threshold between short-term and long-term unemployment. They find that the exemption is very rarely used and that the minimum wage binds irrespective of past unemployment duration. While the minimum wage led to a relative rise in entry wages for the long-term unemployed compared to the short-term unemployed, the authors do not detect a relative deterioration in their employment prospects.


Author(s):  
Adam L. Aiken ◽  
Christopher P. Clifford ◽  
Jesse A. Ellis ◽  
Qiping Huang

Abstract We exploit the expiring nature of hedge fund lockups to create a new measure of funding liquidity risk that varies within funds. We find that hedge funds with lower funding risk generate higher returns, and this effect is driven by their increased exposure to equity-mispricing anomalies. Our results are robust to a variety of sampling criteria, variable definitions, and control variables. Further, we address endogeneity concerns in various ways, including a placebo approach and regression discontinuity design. Collectively, our results support a causal link between funding risk and the ability of managers to engage in risky arbitrage.


Author(s):  
Alexander E Ko

Abstract Pest management professionals aim to answer two primary questions for their customers: 1) ‘Where/What is the pest?’ and 2) ‘How do I kill it?’. These two questions drive at the core of any pest management program. 2020 was an exciting year for entomology research, with much work being done on novel technologies and methods for detecting and controlling pests. The objectives of the current publication were to discuss papers published in 2020 that addressed the key pest management objectives of 1) monitoring and 2) controlling pest populations.


2019 ◽  
Vol 188 (6) ◽  
pp. 987-990
Author(s):  
Nicole E Basta ◽  
M Elizabeth Halloran

Abstract The regression discontinuity design (RDD), first proposed in the educational psychology literature and popularized in econometrics in the 1960s, has only recently been applied to epidemiologic research. A critical aim of infectious disease epidemiologists and global health researchers is to evaluate disease prevention and control strategies, including the impact of vaccines and vaccination programs. RDDs have very rarely been used in this context. This quasi-experimental approach using observational data is designed to quantify the effect of an intervention when eligibility for the intervention is based on a defined cutoff such as age or grade in school, making it ideally suited to estimating vaccine effects given that many vaccination programs and mass-vaccination campaigns define eligibility in this way. Here, we describe key features of RDDs in general, then specific scenarios, with examples, to illustrate that RDDs are an important tool for advancing our understanding of vaccine effects. We argue that epidemiologic researchers should consider RDDs when evaluating interventions designed to prevent and control diseases. This approach can address a wide range of research questions, especially those for which randomized clinical trials would present major challenges or be infeasible. Finally, we propose specific ways in which RDDs could advance future vaccine research.


2013 ◽  
Vol 93 (4) ◽  
pp. 639-642 ◽  
Author(s):  
K. W. Reeh ◽  
G. C. Cutler

Reeh, K. W. and Cutler, G. C. 2013. Laboratory efficacy and fungicide compatibility of Clonostachys rosea against Botrytis blight on lowbush blueberry. Can. J. Plant Sci. 93: 639–642. Lowbush blueberry (Vaccinium angustifolium) is an economically important crop. Clonostachys rosea is an endophytic fungus that can provide protection of plants from several pathogens, including Botrytis cinerea. It is unknown if C. rosea is able to colonize and protect V. angustifolium, and whether it is tolerant of fungicides commonly used for B. cinerea management in blueberry production. In a greenhouse experiment, pre-treatment of blueberry blossoms with C. rosea significantly reduced establishment of B. cinerea, but treatments after establishment of the pathogen were not effective. Clonostachys rosea demonstrated in vitro tolerance to the fungicide Switch®, but little or no tolerance to Pristine® and Maestro®. Our results are encouraging for additional field research examining the use of C. rosea as part of an integrated pest management program for B. cinerea control on lowbush blueberries.


2020 ◽  
Vol 52 (2) ◽  
pp. 289-315
Author(s):  
Caitlin Andrews-Lee

Scholars suggest that charismatic movements must institutionalize to survive beyond the death of the founder. Yet charismatic movements around the world that have maintained their personalistic nature have persisted or reemerged. This article investigates the conditions under which politicians can use their predecessors' charismatic legacies to revive these movements and consolidate power. I argue that three conditions - the mode of leadership selection, the presence of a crisis, and the ability to conform to the founder's personalistic nature - shape successors' capacity to pick up their forefather's mantle and restore the movement to political predominance. To demonstrate my theory, I trace the process through which some leaders succeeded while others failed to embody the founder's legacy across three charismatic movements: Argentine Peronism, Venezuelan Chavismo, and Peruvian Fujimorismo. Alexander Lee, Incumbency, Parties, and Legislatures: Theory and Evidence from India Incumbent legislators in some developing countries are often thought to face an electoral disadvantage relative to challengers. This article traces this effect to high levels of centralization within the political parties and governments of these countries. In political systems dominated by party leaders, legislators face substantial formal and informal constraints on their ability to influence policy, stake positions, and control patronage, which in turn reduce their ability to build up personal votes. This theory is tested on a dataset of Indian national elections since 1977, using a regression discontinuity design to measure the effects of incumbency. Candidates less affected by centralization - those from less-centralized political parties and from parties not affected by restrictions on free parliamentary voting - have a low or non-existent incumbency disadvantage.


1979 ◽  
Vol 111 (10) ◽  
pp. 1101-1109 ◽  
Author(s):  
M. T. AliNiazee

AbstractA phenology model based on a time–temperature relationship has been developed for the western cherry fruit fly, Rhagoletis indifferens Curran. The model predicts the occurrence of various biological events such as emergence levels, mating, oviposition, larval appearance, parasite activity, and pupation. These events are predicted as a function of summation of thermal units (TU) starting 1 March. For example, emergence begins at 462, oviposition at 541, hatch at 594, and pupation at 795 TU. The model was validated by actual field observations for a period of 3 years (1976–1978). Extended validation of first emergence was obtained from an entirely different cherry growing area, the Hood River Valley. The model could be a useful tool in integrated pest management program on cherries.


2010 ◽  
Vol 103 (2) ◽  
pp. 409-415 ◽  
Author(s):  
Roger I. Vargas ◽  
Ronald F. L. Mau ◽  
John D. Stark ◽  
Jaime C. Piñero ◽  
Luc Leblanc ◽  
...  

2020 ◽  
Vol 52 (2) ◽  
pp. 311-331
Author(s):  
Alexander Lee

Incumbent legislators in some developing countries are often thought to face an electoral disadvantage relative to challengers. This article traces this effect to high levels of centralization within the political parties and governments of these countries. In political systems dominated by party leaders, legislators face substantial formal and informal constraints on their ability to influence policy, stake positions, and control patronage, which in turn reduce their ability to build up personal votes. This theory is tested on a dataset of Indian national elections since 1977, using a regression discontinuity design to measure the effects of incumbency. Candidates less affected by centralization-those from less-centralized political parties and from parties not affected by restrictions on free parliamentary voting - have a low or non-existent incumbency disadvantage.


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