Savings and technology choice for risk averse farmers

Farmers in developing countries have limited opportunities for borrowing to even out variability associated with risky farm income, but they can save. A dynamic programming model of savings is presented in the current paper which examines optimal savings strategies for farmers, using a case study of integrated rice-shrimp farms in Vietnam. It is shown that when savings are accounted for, the expected utility ranking of different risky farm choices may not differ that much between farmers with different levels of risk aversion.Farm Management, Risk and Uncertainty,

The economics of land degradation and technological change: a case study in Vietnam

This paper explores the economics of land degradation in the rice-shrimp system in the Mekong Delta of Vietnam. A bioeconomic NPV model was developed to evaluate and compare the long-term benefits of alternative production choices and farm technologies. There is an alternative rice-shrimp technology emerging in Vietnam that does not have the same land degrading impacts as the 'traditional' system, however the high capital outlay and risk associated with such technology presents its own problems. In the paper the economic incentives for adoption of the non-land degrading rice-shrimp technology are explored. Conclusions are drawn with regard to the opportunity cost of land degradation and technological change. Some conclusions are also provided on the policy implications arising from the results presented.land degradation, technological change, Vietnam, Environmental Economics and Policy,

Current and future demand for irrigation water in Western Australia

This report contains the results of a study commissioned by the Department of Agriculture to investigate the economic factors that may impact on the future demand for water in Western Australia

The welfare costs of urban outdoor water restrictions

Outdoor water restrictions are usually implemented as bans on a particular type of watering technology (sprinklers), which allow households to substitute for labour-intensive (hand-held) watering. This paper presents a household production model approach to analysing the impact of sprinkler restrictions on consumer welfare and their efficacy as a demand management tool. Central to our empirical analysis is an experimentally derived production function which describes the relationship between irrigation and lawn quality. We demonstrate that for a typical consumer complete sprinkler bans may be little more effective than milder restrictions policies, but are substantially more costly to the household.household model, urban water demand, urban water restrictions, Resource /Energy Economics and Policy,

Valuing Urban Wetlands of the Gnangara Mound: A Hedonic Property Price Approach in Western Australia

Up to 60% of potable water supplied to Perth in Western Australia is extracted from the Gnangara mound. Many of the urban wetlands above the Mound are groundwater-dependent. Excessive groundwater extraction and climate change have resulted in a decline in water levels in the wetlands. This study estimates the value of urban wetlands in three local government districts in the Perth metropolitan region using the hedonic property price approach. Preliminary results found that proximity to wetlands influences the sales prices of properties. The marginal implicit price of reducing the distance to the nearest wetland by 1 metre, evaluated at the mean sales value, is AU$463. If there is more than one wetland within 1.5 kilometres of a property, the second wetland will help increase the property price by AU$6,081. For a 50 ha wetland, we estimate the total premium of on sales due to wetland proximity is AU$220 million, based on average property characteristics and medium house density. These results will help inform policy makers and land developers on the value of conserving existing urban wetlands, creating new wetland areas and urbanising rural wetlands.groundwater, housing development, aquifer, marginal implicit price, Land Economics/Use,

A Bio-economic Model of a Shrimp Hatchery in the Mekong River Delta of Vietnam

Shrimp culture areas and production of the Mekong Delta cover about 60 percent of the total shrimp areas and production of Vietnam. Especially, the Delta contributes about 80 percent of the total shrimp production for export. Rapid development of the shrimp industry is raising a number of serious problems that need to be solved. Shrimp seed supply (post larvae production) plays an essential role in the shrimp industry and it is one of the most important constraints to the development of the shrimp industry in the Delta. The focus of this study is aimed at obtaining an improvement in both the profit per day and post larvae production of the shrimp hatchery in the Mekong River Delta of Vietnam. A Monte Carlo simulation approach was applied to develop a stochastic and dynamic bio-economic model of a shrimp hatchery in the Delta. Initial results and policy recommendations are based on the analysis of the hatchery system simulation using a forward recursion approach and by changing the most important assumptions.Shrimp hatchery, larval stage, system simulation modelling, Agricultural and Food Policy, Production Economics,

Price formation on the Northern Victorian water exchange

The opportunity cost of water in the irrigation industry is a contentious issue at present because of the commitment made by the State and Commonwealth governments to get water out of the irrigation industry for environmental flows. The estimated value of the opportunity cost will affect farmers' claims for compensation. Variation in the opportunity cost over space and the functioning of the spatial market will determine whether the efficiency costs of a simple across the board reduction in rights can be mitigated by trade or whether strategic buy back of water is required. The extent of variation in the opportunity cost of water according to seasonal conditions will affect the cost of flow policies that impact on the reliability of rights. To date, most economic advice on this opportunity cost of water has centred on gross margin analysis of the main irrigation uses of water and the compensation of these industries across space compared to the quantity of rights held. However, there has been a large volume of trade on temporary water markets in recent years and there is potential for using this data to better understand some of the characteristics of water demand and the market for water. This paper presents a preliminary analysis of market data from the last 5 years of trade on the Northern Victorian water exchange. The nature of bidding behaviours and spatial and temporal variations in water prices is illustrated, and the impact of water allocations and seasonal conditions on water prices is estimated.Demand and Price Analysis, Resource /Energy Economics and Policy,

Fetal renal parenchyma: evaluation of a novel ultrasound measurement to assess kidney development

Introduction: Abnormal fetal growth can adversely impact renal development and is associated with increased risks of developing hypertension and chronic kidney disease later in life. A non-invasive, sensitive method of assessing normal and abnormal fetal kidney development is required. We hypothesise that the fetal renal parenchymal thickness could be used to evaluate the development of the fetal kidneys and provide an indirect estimate of fetal nephron number. This study uses antenatal ultrasound to assess fetal renal parenchymal growth and blood flow to determine if these are affected by abnormal fetal growth. Methods: A longitudinal, observational study was conducted at the Townsville Hospital, Townsville, Australia between May 2017 to December 2018. Mixed risk women with an accurately dated, singleton pregnancy underwent a pregnancy ultrasound scan at least every four weeks between 16 and 40 weeks gestation. Renal parenchymal thickness and echogenicity, renal volume, fetal growth biometries, amniotic fluid measurements, renal artery Doppler and other fetal Dopplers were assessed in appropriately grown, fetal growth restriction or large for gestational age fetuses. Results: 155 participants were recruited, with 7 participants excluded due to fetal abnormalities. Mixed effects modelling was used so that variations between gestational ages within fetuses and between fetuses was considered. A reference graph was developed for normal fetal renal parenchymal growth. In growth restricted fetuses the renal parenchymal thickness was found to be significantly less when compared to the parenchymal thickness of appropriately grown fetuses. Conclusions: Measurement of the renal parenchymal thickness is an innovative method to evaluate the development of the fetal kidneys. This new chart of fetal renal parenchymal thickness may be useful for the diagnosis of nephropathologies and the identification of infants at risk of kidney disease. Fetal growth restriction was found to adversely affect the renal parenchymal growth. This suggests growth restricted fetuses are born with fewer nephrons and are therefore likely to be more susceptible to hypertension and early onset kidney disease later in life

International Communications

Introduction: Disorders of fetal growth, such as intrauterine growth restriction (IUGR) and large for gestational age (LGA), have been found to have a profound effect on the development of the fetal kidney. Abnormal kidney development is associated with hypertension and chronic kidney disease later in life. This study will use a novel ultrasound measurement to assess the renal parenchymal growth and kidney arterial blood flow in the fetus to evaluate the development of the fetal kidneys and provide an indirect estimate of nephron number. Measurements in normally grown, IUGR and LGA fetuses will be compared to determine if changes in renal parenchymal growth can be detected in utero. Methods and analysis: This longitudinal, prospective, observational study will be conducted over 12 months in the Ultrasound Department of the Townsville Hospital, Australia. The study will compare fetal renal parenchymal thickness (RPT) and renal artery Doppler flow between IUGR fetuses and appropriately grown fetuses, and LGA fetuses and appropriately grown fetuses between 16 and 40 weeks. The fetal RPT to renal volume ratio will also be compared, and correlations between RPT, renal parenchymal echogenicity, fetal Doppler indices and amniotic fluid levels will be analysed. Ethics and dissemination: This study was approved by the Townsville Health District Human Research Ethics Committee. The study results will form part of a thesis and will be published in peer-reviewed journals and disseminated at international conferences

Kidney growth following preterm birth: evaluation with renal parenchyma ultrasonography

Background: Preterm birth impairs nephrogenesis, leading to a reduced nephron endowment which is inextricably linked to hypertension and chronic kidney disease in adults. The aim of this study was to compare nephron endowment between preterm infants to that of intrauterine fetuses at the same gestational age (GA) using a novel indirect ultrasound measurement of the renal parenchymal thickness. We hypothesized that extrauterine and intrauterine renal parenchymal thickness would differ based on altered renal growth environments. Methods: In this observational study, appropriately grown preterm infants (birth weight of between the 5th and 95th percentile) born <32 weeks, admitted to the neonatal department were eligible to participate. Renal parenchymal thickness of the infants was measured at 32- and 37-weeks postmenstrual age (PMA). These measurements were compared to the intrauterine renal parenchymal thickness of appropriately grown fetuses (control). Results: At 32-weeks PMA, the preterm infants had a significantly thinner renal parenchyma compared to fetuses at 32-weeks GA suggesting they had less nephrons, however by 37-weeks there was no significant difference in renal parenchymal thickness. Conclusions: We propose that the differences in the extrauterine growth of the renal parenchyma in preterm infants may be due to a reduced number of nephrons and compensatory hyperfiltration. Impact: This article provides insight into the effects of prematurity on nephrogenesis by comparing extrauterine renal parenchymal growth of born preterm infants to the ideal intrauterine fetal growth. Renal parenchyma thickness measurement using ultrasonography is a novel non-invasive measurement of renal development for the determination of nephron endowment. Differences in the renal parenchymal thickness of the preterm infants may be due to a deficit in nephron number and compensatory hyperfiltration