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A key question for climate change adaptation is whether existing cropping systems can become less sensitive to climate variations. We use a field-level data set on maize and soybean yields in the central United States for 1995 through 2012 to examine changes in drought sensitivity. Although yields have increased in absolute value under all levels of stress for both crops, the sensitivity of maize yields to drought stress associated with high vapor pressure deficits has increased. The greater sensitivity has occurred despite cultivar improvements and increased carbon dioxide and reflects the agronomic trend toward higher sowing densities. The results suggest that agronomic changes tend to translate improved drought tolerance of plants to higher average yields but not to decreasing drought sensitivity of yields at the field scale.

Reducing regional economic disparities in China is an important task to facilitate inclusive and sustainable long-term economic growth. This paper investigates the role of technological innovation in facilitating regional economic convergence in China (i.e., narrowing the gap between more developed and less developed provinces). We utilize a province-level panel data set from 1998 to 2017 to calculate the so-called sigma (σ) and beta (β) regional economic convergence indexes, which allows us to examine the patterns of convergence in China over time. In particular, we use panel data regression models to calculate β indexes and examine how various measures of technological innovation influence regional economic convergence in China. Findings from our empirical analysis suggest that the provincial economies were diverging from 1998 to 2006. However, we observe regional economic convergence in China after 2006. Moreover, we find that technological innovation promoted regional economic convergence post-2006, and there is evidence that technological innovation spills over and benefits nearby surrounding provinces. We also find that transfer payments made by the Chinese central government to the provinces help boost regional economic growth and narrow regional economic disparities.

The short‐run effects of cover crop use on cash crop yields (e.g., corn [Zea mays L.] and soybeans [Glycine max (L.) Merr.]) have been a topic of debate given that evidence from previous literature has generally been mixed on this issue. Past studies suggest that the observed yield effect varies (i.e., negative, positive, or insignificant), often depending on the applied cover crop species used, weather conditions, and farm management practices implemented (among others). In this study, we examine the short‐run (i.e., 1 year) yield impact of four different cover crop families—grasses (Poaceae), broadleaves (Brassicaceae), legumes (Fabaceae), and others—both as single‐family groups and as mixtures. Data from side‐by‐side on‐farm experimental plots in six Eastern US states were collected from 2017 to 2019 in order to achieve the objective of the study. Statistical analysis of this multi‐year plot‐level data suggests that the majority of the cover crop families and mixtures investigated in this study do not have a statistically significant short‐run effect on subsequent corn yields. In some cases, cover crop treatment even resulted in short‐run yield losses (i.e., a yield penalty). These results imply that cash crop yield benefits from cover crop adoption are likely not going to be observed with just 1 year of use. This lack of immediate economic benefit may explain the relatively low cover crop adoption rate currently observed in the United States and the need for upfront cost‐share subsidy payments to encourage further uptake of this practice. Core Ideas The short‐run yield effect of different cover crop families was examined. Cover crop families and mixtures have mostly no short‐run effect on corn yields. The lack of immediate economic benefit explains the low cover crop adoption rate. Plain Language Summary Cover crops, like grasses, legumes, and broadleaves, are often used in farming to improve soil health and reduce erosion. However, their impact on the following year's crop yields, like corn and soybeans, is debated. This study looked at how four cover crop families — grasses, broadleaves, legumes, and others — affect corn yields in the short term (one year) on farms in six states in the Eastern U.S. The research found that most cover crops did not significantly impact corn yields in the short term. In some cases, using cover crops even led to slight yield losses. This suggests that immediate yield benefits from cover crops may not be seen after just one year. The study shows that cover crops may not provide quick economic benefits, which could explain why many U.S. farmers are hesitant to adopt them. To encourage more farmers to use cover crops, financial support like subsidies may be needed to cover the initial costs.

This article develops a procedure for weighting historical loss cost experience based on longer time-series weather information. Using a fractional logit model and out-of-sample competitions, weather variables are selected to construct an index that allows proper assessment of the relative probability of weather events that drive production losses and to construct proper “weather weights” that are used in averaging historical loss cost data. A variable-width binning approach with equal probabilities is determined as the best approach for classifying each year in the shorter historical loss cost data used for rating. When the weather-weighting approach described above is applied, we find that the weather-weighted average loss costs at the national level are different from the average loss costs without weather weighting for all crops examined.

This study addresses how participation in the Federal crop insurance program influences agricultural loan delinquencies. To achieve this objective, we use 1994–2015 county‐level panel data for corn production in the Midwestern United States (US). Traditional linear fixed effect (FE) models, instrumental variable‐based FE estimation, and several robustness checks are used in the empirical analysis. Estimation results suggest that counties with higher levels of crop insurance participation tend to have statistically lower rates of agricultural loan delinquency. This is evidence that the US crop insurance program helps reduce financial stress and facilitates the continued viability of the agricultural credit system.

Using country-level panel data from 1950 to 2003, this paper critically examines the impact of the US Visa Waiver Program (VWP) on bilateral trade levels. Our empirical analysis uses a variety of specifications, estimators, and robustness checks, including a \"random growth\" specification that controls for selection bias from both time-varying and time-invariant unobserved country-specific characteristics. The results indicate that a temporary foreign visitor policy with less requirements, such as the US VWP, tends to increase the bilateral trade levels between the US and the selected VWP countries, especially for US exports. This suggests that VWP may have encouraged business travel and commerce enough such that there are export benefits from this less restrictive temporary foreign visitor policy of about 10–20% (~2-4% in tariff equivalent terms).

This study explores how higher temperatures influence corn yield response to planting density. Using 1990–2010 field trial data from Wisconsin and econometric models with a variety of specifications, we find that higher temperatures reduce the yield benefits of increasing planting density. However, these adverse high-temperature effects are smaller for genetically modified corn varieties, especially those with rootworm-resistant traits. Consistent with previous studies, these results support the notion that varietal improvements through genetic modification may have paved the way for higher planting densities in US corn production. Moreover, our results imply that expected in-season temperatures are important considerations when making planting density decisions.

In the era of climate change, rice ( Oryza sativa L.) production is increasingly affected by the rising frequency and severity of various abiotic stresses such as flood and drought. In some cases, 100 % yield loss can be attributed solely to these stresses. Hence, there is an urgent need to develop climate-smart rice that is more resilient to abiotic stresses. As the development and dissemination of climate-smart rice varieties entail costs, this article examines the net economic benefits of developing and disseminating successful drought-tolerant rice in South Asia where rice area prone to drought far outweighs area with other abiotic stresses. Drought causes major rice yield losses not only in South Asia but also in other parts of Asia and Africa. Using the ORYZA2000 (ORYZA model series were developed at the International Rice Research Institute (IRRI) in the early 1990s in collaboration with Wageningen University and Research Centre (WUR) and 16 national agricultural research and extension systems in Asia. ORYZA2000 is an update and integration of earlier versions of the ORYZA model. More detailed documentation of ORYZA2000 can be found in ( http://books.irri.org/9712201716_content.pdf )) crop growth simulation model, we demonstrate that a successful drought-tolerant rice variety can provide yield gains in South Asia of a minimum of 1.71 % to a maximum of 8.96 % when there is no change in the climate and under different climate scenarios projected by Canadian General Circulation Models (CGCMs). Moreover, our economic analysis shows that the economic benefits from the successful development and dissemination of droughttolerant rice more than outweigh the research investments needed to develop a variety. Although the research, development, and dissemination of a climate-smart drought-tolerant rice variety in the South require USD 84 million, our economic model indicates that rice production will be higher by a minimum of 6 million tons worth USD 3.3 billion, and rice prices will be lower by a minimum of USD 72 per ton when a drought-tolerant variety is adopted in South Asia (as compared to the case without this new variety). This can lead to improved rice food security and better nutritional outcomes for the poor.

We measure the economic impact of varietal improvement and technological change in flue-cured tobacco across quantity (e.g., yield) and quality dimensions under a voluntary quality constraint. Since 1961, flue-cured tobacco breeders in the United States have been subject to the Minimum Standards Program that sets limits on acceptable quality characteristics for commercial tobacco varieties. We implement a Bayesian hierarchical model to measure the contribution of breeding efforts to changes in tobacco yields and quality between 1954 and 2017. The Bayesian model addresses limited data for varieties in the trials and allows easy generation of the necessary parameters of economic interest.

This article examines the impact of two Integrated Pest Management information dissemination approaches on insecticide use and efficiency of Vietnamese rice farmers. Specifically, we investigate the impact of Farmer Field Schools (FFS) and \"No Early Spray\" (NES) mass media campaigns by utilizing econometric approaches that control for endogeneity and selection problems. Our results suggest that farmers exposed to FFS and NES information are more technically efficient than control farmers who have not been exposed to information from FFS or NES. However, only FFS farmers, not NES farmers, seem to have significantly reduced their insecticide use relative to non-FFS or non-NES control farmers.