DETERMINANTS OF VIRTUAL WATER TRADE OF CEREAL CROPS IN SAUDI ARABIA

2020 ◽  
Vol 51 (4) ◽  
pp. 1118-1127
Author(s):  
Y. Alamri ◽  
M. Reed ◽  
S. Saghaian
Keyword(s):  
Saudi Arabia ◽  
Fixed Effects ◽  
Virtual Water ◽  
Agricultural Trade ◽  
Cereal Crops ◽  
Final Model ◽  
Pseudo Maximum Likelihood ◽  
Water Imports ◽  
Country Effect ◽  
Specific Country

In this research, we used a gravity model to investigate whether water scarcity variables influence agricultural trade of cereal crops for Saudi Arabia. We compare the OLS, Fixed effects, Random effects, and Poisson Pseudo-Maximum Likelihood (PPML) estimators to determine the best model. The AIC, and multicollinearity, heteroskedasticity, and autocorrelation tests assist in determining estimation procedures and the final model. We cluster the errors by distance to improve the specific country effect variables, such as economic mass. We find that water-related variables influence virtual water imports of cereals, millet, corn, barely, and sesame.

Food and Water Security in West Asia

2018 ◽  
pp. 512-529
Author(s):  
Eckart Woertz
Keyword(s):  
Role Model ◽  
Value Added ◽  
Water Security ◽  
Virtual Water ◽  
Agricultural Trade ◽  
Economic Sectors ◽  
Trade Surplus ◽  
Self Sufficiency ◽  
Water Scarce ◽  
Policy Solutions

West Asia is one of the most water-scarce regions of the world and one of its foremost importers of virtual water despite sustained efforts at self-sufficiency, especially in cereal production. Technology-oriented policy solutions eye a reorientation of agriculture towards fruit and vegetables that are less water-intensive than cereals and provide more value added per water unit consumed. Turkey is a role model here; the country has an agricultural trade surplus and ranks among the top ten agricultural economies globally in value terms. Yet technology-oriented policy prescriptions overlook the sociopolitical ‘problemsheds’ that emerge (along with new agro-lobbies) and agriculture as the main water consumer has to compete with other economic sectors and sprawling urbanization. This article looks at the different categories of countries and their specific challenges.

scholarly journals Assessment of Main Cereal Crop Trade Impacts on Water and Land Security in Iraq

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 98 ◽  
Author(s):  
Salam Hussein Ewaid ◽  
Salwan Ali Abed ◽  
Nadhir Al-Ansari
Keyword(s):  
Water Resource Management ◽  
Management Practices ◽  
Water Footprint ◽  
Irrigation Management ◽  
Virtual Water ◽  
Cereal Crops ◽  
Scarce Water ◽  
The Impact ◽  
Selection Of ◽  
Resources Assessment

Growing populations, socio-economic development, the pollution of rivers, and the withdrawal of fresh water are all signs of increasing water scarcity, and with 85% of global use, agriculture is the biggest freshwater user. The water footprint (WF) and virtual water (VW) are concepts used recently for freshwater resources assessment. The WF reflects how much, when and where the water was used whereas VW reveals the volume of water embedded in goods when traded. The first goal of this research is to determine the WF per ton and the WF of production (Mm3/yr) of wheat, barley, rice, and maize in Iraq. The second goal is estimating the quantities of the 4 main cereal crops imported into Iraq and assessing the impact on reducing WF and land savings for 10 years from 2007 to 2016. The results showed that the WF per ton was 1736, 1769, 3694, 2238 m3/ton and the WF of production was 5271, 1475, 997, 820 Mm3/yr for wheat, barley, rice, and maize, respectively. The median total VW imported was 4408 Mm3/yr, the largest volume was 3478 Mm3/yr from wheat, and Iraq saved about 2676 Mm3 of irrigated water and 1,239,539 M ha of land by importing crops every year during 2007–2016. The study revealed the significance of better irrigation management methods to decrease the WF through a selection of crops that need less water and cultivation in rain-fed areas, as well as the use of cereal import to conserve scarce water resources, which is crucial both in terms of water resource management and preservation of the environment. The results of this research could be used as a guideline for better water management practices in Iraq and can provide helpful data for both stakeholders and policymakers.

scholarly journals Sustainable Water Use for International Agricultural Trade: The Case of Pakistan

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2259 ◽  
Author(s):  
Tariq Ali ◽  
Abdul M. Nadeem ◽  
Muhammad F. Riaz ◽  
Wei Xie
Keyword(s):  
Food Security ◽  
Water Use ◽  
Fruits And Vegetables ◽  
Virtual Water ◽  
Agricultural Trade ◽  
Agricultural Commodities ◽  
Virtual Water Trade ◽  
Use Of Resources ◽  
Sustainable Water Use

Sustainable use of resources is critical, not only for people but for the whole planet. This is especially so for freshwater, which in many ways determines the food security and long-term development of nations. Here, we use virtual water trade to analyze the sustainability of water used by Pakistan in the international trade of 15 major agricultural commodities between 1990 and 2016 and in 2030. Most of the existing country-level studies on virtual water trade focused on net virtual water importers, which are usually water-scarce countries as well. This is the first study to concentrate on a water-stressed net virtual water-exporting country. Our results show that Pakistan has been trading large and ever-increasing volumes of virtual water through agricultural commodities. Despite the overall small net export of total virtual water per year, Pakistan has been a net-exporter of large quantities of blue (fresh) virtual water through its trade, even by fetching a lower value for each unit of blue water exported. Given Pakistan’s looming water scarcity, exporting large volumes of blue virtual water may constrain the country’s food security and long-term economic development. Improving water use efficiency for the current export commodities, for example, rice and exploring less water-intensive commodities, for example, fruits and vegetables, for export purposes can help Pakistan achieve sustainable water use in the future.

scholarly journals Fast Poisson estimation with high-dimensional fixed effects

2020 ◽  
Vol 20 (1) ◽  
pp. 95-115 ◽  
Author(s):  
Sergio Correia ◽  
Paulo Guimarães ◽  
Tom Zylkin
Keyword(s):  
Least Squares ◽  
Fixed Effects ◽  
Maximum Likelihood Estimates ◽  
High Dimensional ◽  
Software Components ◽  
Iteratively Reweighted Least Squares ◽  
Convergence Properties ◽  
New Techniques ◽  
Boston College ◽  
Pseudo Maximum Likelihood

In this article, we present ppmlhdfe, a new command for estimation of (pseudo-)Poisson regression models with multiple high-dimensional fixed effects (HDFE). Estimation is implemented using a modified version of the iteratively reweighted least-squares algorithm that allows for fast estimation in the presence of HDFE. Because the code is built around the reghdfe package ( Correia, 2014 , Statistical Software Components S457874, Department of Economics, Boston College), it has similar syntax, supports many of the same functionalities, and benefits from reghdfe‘s fast convergence properties for computing high-dimensional leastsquares problems. Performance is further enhanced by some new techniques we introduce for accelerating HDFE iteratively reweighted least-squares estimation specifically. ppmlhdfe also implements a novel and more robust approach to check for the existence of (pseudo)maximum likelihood estimates.

scholarly journals Analysis of Trade-offs between Food Security and Water-Land Savings through Food Trade and Structural Changes of Virtual Water Trade in the Arab World

2018 ◽  
Author(s):  
Sang-Hyun Lee ◽  
Rabi H. Mohtar ◽  
Seung-Hwan Yoo
Keyword(s):  
Saudi Arabia ◽  
Food Security ◽  
Structural Changes ◽  
Arab World ◽  
Virtual Water ◽  
Virtual Water Trade ◽  
Food Trade ◽  
Trade Offs ◽  
Crop Area ◽  
Shed Light

Abstract. The aim of this study is to analyze the impacts of food trade on food security and water-land savings in the Arab World in terms of virtual water trade (VWT). We estimated the total volume of virtual water imported for four major crops – barley, maize, rice, and wheat – from 2000 to 2012, and assessed their impacts on water and land savings, and food security. The largest volume of virtual water was imported by Egypt (19.9 billion m3/year), followed by Saudi Arabia (13.0 billion m3/year). Accordingly, Egypt would save 13.1 billion m3 in irrigation water and 2.1 million ha of crop area through importing crops. In addition, connectivity and influence of each country in the VWT network was analyzed using degree and eigenvector centralities. The study revealed that the Arab World focused more on increasing the volume of virtual water imported during the period 2006–2012 with little attention to the expansion of connections with country exporters, which is a vulnerable expansion. This study shed light on opportunities and risks associated with VWT and its role in food security and land management in the Arab World.

scholarly journals Water footprints of cities – indicators for sustainable consumption and production

2013 ◽  
Vol 10 (2) ◽  
pp. 2601-2639 ◽  
Author(s):  
H. Hoff ◽  
P. Döll ◽  
M. Fader ◽  
D. Gerten ◽  
S. Hauser ◽  
...  
Keyword(s):  
Water Footprint ◽  
Sustainable Consumption ◽  
Virtual Water ◽  
External Source ◽  
Trade Integration ◽  
Export Production ◽  
Source Regions ◽  
Context Specific ◽  
Water Scarce ◽  
Water Imports

Abstract. Water footprints have been proposed as sustainability indicators, relating the consumption of goods like food to the amount of water necessary for their production and the impacts of that water use in the source regions. We have further developed the existing water footprint methodology by globally resolving virtual water flows and import and source regions at 5 arc minutes spatial resolution, and by assessing local impacts of export production. Applying this method to three exemplary cities, Berlin, Delhi and Lagos, we find major differences in amounts, composition, and origin of green and blue virtual water imports, due to differences in diets, trade integration and crop water productivities in the source regions. While almost all of Delhi's and Lagos' virtual water imports are of domestic origin, Berlin on average imports from more than 4000 km distance, in particular soy (livestock feed), coffee and cocoa. While 42% of Delhi's virtual water imports are blue water based, the fractions for Berlin and Lagos are 2% and 0.5%, respectively, roughly equal to local drinking water abstractions of these cities. Some of the external source regions of Berlin's virtual water imports appear to be critically water scarce and/or food insecure. However for deriving recommendations on sustainable consumption and trade, further analysis of context-specific costs and benefits associated with export production will be required.

scholarly journals Trends in and Predictors of Carbapenem Consumption across North American Hospitals: Results from a Multicenter Survey by the MAD-ID Research Network

2019 ◽  
Vol 63 (7) ◽  
Author(s):  
Nathaniel J. Rhodes ◽  
Jamie L. Wagner ◽  
Susan L. Davis ◽  
John A. Bosso ◽  
Debra A. Goff ◽  
...  
Keyword(s):  
North American ◽  
Fixed Effects ◽  
The United States ◽  
Mixed Effects ◽  
Research Network ◽  
Beta Lactam ◽  
Final Model ◽  
Days Of Therapy ◽  
Multicenter Survey ◽  
Consumption Rates

ABSTRACT We sought to define trends in and predictors of carbapenem consumption across community, teaching, and university-affiliated hospitals in the United States and Canada. We conducted a retrospective multicenter survey of carbapenem and broad-spectrum noncarbapenem beta-lactam consumption between January 2011 and December 2013. Consumption was tabulated as defined daily doses (DDD) or as days of therapy (DOT) per 1,000 patient days (PD). Multivariate mixed-effects models were explored, and final model goodness of fit was assessed by regressions of observed versus predicted values and residual distributions. A total of 20 acute-care hospitals responded. The centers treated adult patients (n = 19/20) and pediatric/neonatal patients (n = 17/20). The majority of the centers were nonprofit (n = 17/20) and not affiliated with medical/teaching institutions (n = 11/20). The median (interquartile range [IQR]) carbapenem consumption rates were 38.8 (17.4 to 95.7) DDD/1,000 PD and 29.7 (19.2 to 40.1) DOT/1,000 PD overall. Carbapenem consumption was well described by a multivariate linear mixed-effects model (fixed effects, R2 = 0.792; fixed plus random effects, R2 = 0.974). Carbapenem consumption increased by 1.91-fold/quarter from 48.6 DDD/1,000 PD (P = 0.004) and by 0.056-fold/quarter from 45.7 DOT/1,000 PD (P = 0.93) over the study period. Noncarbapenem consumption was independently related to increasing carbapenem consumption (beta = 0.31 for increasing noncarbapenem beta-lactam consumption; P < 0.001). Regular antibiogram publication and promotion of conversion from intravenous (i.v.) to oral (p.o.) administration independently affected carbapenem consumption rates. In the final model, 58.5% of the observed variance in consumption was attributable to between-hospital differences. Rates of carbapenem consumption across 20 North American hospitals differed greatly, and the observed differences were correlated with hospital-specific demographics. Additional studies focusing on the drivers of hospital-specific carbapenem consumption are needed to determine whether these rates are justifiable.

scholarly journals Time to break the silence around virtual-water imports

Nature ◽  
2008 ◽  
Vol 453 (7195) ◽  
pp. 587-587 ◽  
Author(s):  
Junguo Liu ◽  
H. H. G. Savenije
Keyword(s):  
Virtual Water ◽  
Water Imports

Virtual water flows and trade liberalization

2004 ◽  
Vol 49 (7) ◽  
pp. 25-32 ◽  
Author(s):  
J. Ramirez-Vallejo ◽  
P. Rogers
Keyword(s):  
Water Resources ◽  
Trade Liberalization ◽  
Formal Model ◽  
Explanatory Power ◽  
Value Added ◽  
Virtual Water ◽  
Agricultural Trade ◽  
Virtual Water Trade ◽  
Water Flows ◽  
The Impact

The linkages between agricultural trade and water resources need to be identified and analyzed to better understand the potential impacts that a full liberalization, or lack thereof, will have on water resources. This paper examines trade of virtual water embodied in agricultural products for most countries of the world. The main purpose of the paper, however, is to examine the impact of trade liberalization on virtual-water trade in the future. Based on a simulation of global agricultural trade, a scenario of full liberalization of agriculture was used to assess the net effect of virtual water flows from the relocation of meat and cereals’ trade. The paper also identifies the main reasons behind the changes in the magnitude and direction of the net virtual water trade over time, and shows that virtual water trade flows are independent of water resource endowments, contrary to what the Heckscher-Ohlin Theorem states. Finally, based on a formal model, some input demand functions at the country level are estimated. The estimates of the income and agricultural support elasticities of demand for import of virtual water have the expected sign, and are statistically significant. Variables found to have some explanatory power of the variance of virtual water imports are average income; population; agriculture as value added; irrigated area, and exports of goods and services.

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