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Book part
Publication date: 30 December 2004

Stephen M. Stohs and Jeffrey T. LaFrance

A common feature of certain kinds of data is a high level of statistical dependence across space and time. This spatial and temporal dependence contains useful information…

Abstract

A common feature of certain kinds of data is a high level of statistical dependence across space and time. This spatial and temporal dependence contains useful information that can be exploited to significantly reduce the uncertainty surrounding local distributions. This chapter develops a methodology for inferring local distributions that incorporates these dependencies. The approach accommodates active learning over space and time, and from aggregate data and distributions to disaggregate individual data and distributions. We combine data sets on Kansas winter wheat yields – annual county-level yields over the period from 1947 through 2000 for all 105 counties in the state of Kansas, and 20,720 individual farm-level sample moments, based on ten years of the reported actual production histories for the winter wheat yields of farmers participating in the United States Department of Agriculture Federal Crop Insurance Corporation Multiple Peril Crop Insurance Program in each of the years 1991–2000. We derive a learning rule that combines statewide, county, and local farm-level data using Bayes’ rule to estimate the moments of individual farm-level crop yield distributions. Information theory and the maximum entropy criterion are used to estimate farm-level crop yield densities from these moments. These posterior densities are found to substantially reduce the bias and volatility of crop insurance premium rates.

Details

Spatial and Spatiotemporal Econometrics
Type: Book
ISBN: 978-0-76231-148-4

Open Access
Article
Publication date: 14 June 2019

Elfadil Mohamed Elbashier, Elfadil Mohammed Eltayeb Elbashier, Siddig Esa Idris2, Wuletaw Tadesse, Izzat S.A. Tahir, Abu Elhassan S. Ibrahim, Ashraf M.A. Elhashimi, Sefyan I. Saad, Amani Ahmed Idris and Hala Mohamed Mustfa

The purpose of this paper was to study the genetic variability, heritability, heat tolerance indices and phenotypic and genotypic correlation studies for traits of 250…

1952

Abstract

Purpose

The purpose of this paper was to study the genetic variability, heritability, heat tolerance indices and phenotypic and genotypic correlation studies for traits of 250 elite International Center for Agricultural Research in the Dry Areas (ICARDA) bread wheat genotypes under high temperature in Wad Medani, Center in Sudan.

Design/methodology/approach

Bread wheat is an important food on a global level and is used in the form of different products. High temperature associated with climate change is considered to be a detrimental stress in the future on world wheat production. A total of 10,250 bread wheat genotypes selected from different advanced yield trials introduction from ICARDA and three checks including were grown in two sowing dates (SODs) (1st and 2nd) 1st SOD heat stress and 2nd SOD non-stress at the Gezira Research Farm, of the Agricultural Research Corporation, Wad Medani, Sudan.

Findings

An alpha lattice design with two replications was used to assess the presence of phenotypic and genotypic variations of different traits, indices for heat stress and heat tolerance for 20 top genotypes and phenotypic and genotypic correlations. Analysis of variance revealed significant differences among genotypes for all the characters. A wide range, 944-4,016 kg/ha in the first SOD and 1,192-5,120 kg/ha in the second SOD, was found in grain yield. The average yield on the first SOD is less than that of the secondnd SOD by 717.7 kg/ha, as the maximum and minimum temperatures were reduced by 3ºC each in the second SOD when compared to the first SOD of the critical stage of crop growth shown.

Research limitations/implications

Similar wide ranges were found in all morpho-physiological traits studied. High heritability in a broad sense was estimated for days to heading and maturity. Moderate heritability estimates found for grain yield ranged from 44 to 63.6 per cent, biomass ranged from 37.8 to 49.1 per cent and canopy temperature (CT) after heading ranged from 44.2 to 48 per cent for the first and secondnd SODs. The top 20 genotypes are better than the better check in the two sowing dates and seven genotypes (248, 139, 143, 27, 67, 192 and 152) were produced high grain yield under both 1st SOD and 2nd SOD.

Practical implications

The same genotypes in addition to Imam (check) showed smaller tolerance (TOL) values, indicating that these genotypes had a smaller yield reduction under heat-stressed conditions and that they showed a higher heat stress susceptibility index (SSI). A smaller TOL and a higher SSI are favored. Both phenotypic and genotypic correlations of grain yield were positively and significantly correlated with biomass, harvest index, number of spikes/m2, number of seeds/spike and days to heading and maturity in both SODs and negatively and significantly correlated with canopy temperature before and after heading in both SODs.

Originality/value

Genetic variations, heritability, heat tolerance indices and correlation studies for traits of bread wheat genotypes under high temperature

Details

International Journal of Climate Change Strategies and Management, vol. 11 no. 5
Type: Research Article
ISSN: 1756-8692

Keywords

Article
Publication date: 17 July 2007

Ruth Hollies

The outlook for investment yields is one of the key uncertainties facing the real estate investor at any time. By examining the relationship of yields to other factors…

1242

Abstract

Purpose

The outlook for investment yields is one of the key uncertainties facing the real estate investor at any time. By examining the relationship of yields to other factors across a large number of office markets, in many countries, over five years, the paper aims to establish relationships with important explanatory factors.

Design/methodology/approach

The paper uses a panel estimation to pick up both the relationship between yields and the explanatory variables both in different locations and at different times. By using both a time and location dimension it is thought that a “truer” generic relationship can be estimated. Using this method aggregates all the available information simultaneously to establish the relationship between office yields and explanatory variables.

Findings

The results show that: locations with higher short‐term interest rates will on average have higher yields; liquid markets tend to have lower yields and similarly, transparent markets and markets with longer leases have lower yields.

Originality/value

As well as the practical applications of this analysis, it makes an academic contribution as yields remain poorly understood and most studies examine time series data in only one country. This international study is the fist of its kind.

Details

Journal of Property Investment & Finance, vol. 25 no. 4
Type: Research Article
ISSN: 1463-578X

Keywords

Article
Publication date: 24 April 2009

Sotiris Tsolacos, Kyung‐Min Kim and Ruijue Peng

The purpose of this paper is to examine the variation and dispersion of prime retail yields in eight Asia‐Pacific centres. It seeks to provide empirical evidence on the…

Abstract

Purpose

The purpose of this paper is to examine the variation and dispersion of prime retail yields in eight Asia‐Pacific centres. It seeks to provide empirical evidence on the significance of real estate and capital market influences as systematic drivers of retail yields in the sample of eight cities. The aim is to build a model that enables market participants to obtain base case yield forecasts.

Design/methodology/approach

A panel model is deployed in this study utilising a database of yields of eight years (2001‐2007). The small number of observations for retail yields across cities is addressed with this approach, which combines time‐series and cross‐section data. A fixed‐effect specification allows for city specific influences that partially capture the heterogeneity of cities in the sample. Within this framework the influence of time varying factors across markets and random effects on yields is examined.

Findings

The empirical estimates established significant influences from real rent growth and interest rates on retail yields explaining 78 per cent of their variation when allowed for fixed effects. Systematic time influences and market size are not significant. Retail yields are found fairly sensitive to long‐term interest (LTI) rates with 1 per cent change in LTI rates resulting in an over 80 basis points shift in yields. In general, investors should be aware of interest rate shocks as these can move retail yields in the region significantly. Based on the actual and simulated values for 2007 Shanghai and Hong Kong are broadly fairly priced. In Tokyo, Sydney and Singapore retail yields are somewhat lower than the simulated values, which are attributed to greater liquidity and transparency in these markets than indicating over‐pricing. In Delhi, the prime yield above the actual a sign of a possible outward movement is found. Beijing appears under‐priced. Finally, in Mumbai, which has the highest yield in the sample, the simulated yield is below actual as per 2007. An adjustment may not be expected as this difference is attributed to the pricing of supply risks in this market.

Originality/value

This study addresses the dearth of research work on retail yields in the Asia‐Pacific region. Through the panel methodology proposed market participants can obtain fundamentals‐based forecasts for prime retail yields in the sample of the eight cities, understand the exposure to interest rate movements and make calls as to whether markets are mispriced. The study shows that pooling data and panel techniques represent a good option to study market dynamics in situations of small datasets.

Details

Journal of Property Investment & Finance, vol. 27 no. 3
Type: Research Article
ISSN: 1463-578X

Keywords

Article
Publication date: 18 November 2019

Royal Madan, Kashinath Saha and Shubhankar Bhowmick

The limit elastic speed of rotating disk is an important design criterion, as it defines the limit before onset of yielding initiates. The purpose of this paper is to…

Abstract

Purpose

The limit elastic speed of rotating disk is an important design criterion, as it defines the limit before onset of yielding initiates. The purpose of this paper is to establish the limit elastic speeds for S-FG disks and report the stresses induced at such speeds.

Design/methodology/approach

For S-FGM disk, effective Young’s modulus is calculated using modified rule of mixture and subsequently effective yield stress is also calculated by taking into consideration of stress-strain transfer ratio. The S-FGM disk is subject to centrifugal loading and the stress and deformation characteristics are investigated using variational principle wherein the solution is obtained by Galerkin’s error minimization principle. Based on von-Mises yield criteria, equivalent stress is calculated at different angular speeds till the equivalent stress at any given location in the disk attains the value of effective yield stress at the given location (location of yield initiation). This defines the limit elastic speed for the S-FGM disk (for given n).

Findings

The limit elastic speed of S-FGM disks for a range of grading index (n) and corresponding stresses within the disk are reported. Results are reported for uniform disks of different aspect ratio and the results reported could be used as practical design data.

Practical implications

Functional grading of material in structures opens a new horizon to explore the possibility of manufacturing high strength component at low weight. Material grading plays a significant role in achieving desired material properties, and literature review reveals reporting of numerous grading functions to approximate material distribution in structure.

Originality/value

The work has not been addressed earlier and findings provide a pioneering insight into the performance of S-FG disks.

Details

World Journal of Engineering, vol. 16 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 2 August 2019

Alejandra Olivares Rios, Gabriel Rodríguez and Miguel Ataurima Arellano

Following Ang and Piazzesi’s (2003) study, the authors use an affine term structure model to study the relevance of macroeconomic (domestic and foreign) factors for Peru’s…

Abstract

Purpose

Following Ang and Piazzesi’s (2003) study, the authors use an affine term structure model to study the relevance of macroeconomic (domestic and foreign) factors for Peru’s sovereign yield curve in the period from November 2005 to December 2015. The paper aims to discuss this issue.

Design/methodology/approach

Risk premia are modeled as time-varying and depend on both observable and unobservable factors; and the authors estimate a vector autoregressive model considering no-arbitrage assumptions.

Findings

The authors find evidence that macro factors help to improve the fit of the model and explain a substantial amount of variation in bond yields. However, their influence is very sensitive to the specification model. Variance decompositions show that macro factors explain a significant share of the movements at the short and middle segments of the yield curve (up to 50 percent), while unobservable factors are the main drivers for most of the movements at the long end of the yield curve (up to 80 percent). Furthermore, the authors find that international markets are relevant for the determination of the risk premium in the short term. Higher uncertainty in international markets increases bond yields, although this effect vanishes quickly. Finally, the authors find that no-arbitrage restrictions with the incorporation of macro factors improve forecasts.

Originality/value

To the authors’ knowledge this is the first application of this type of models using data from an emerging country such as Peru.

Details

Journal of Economic Studies, vol. 46 no. 3
Type: Research Article
ISSN: 0144-3585

Keywords

Article
Publication date: 28 October 2014

Baojing Sun, Changhao Guo and G. Cornelis van Kooten

The paper analyzes the hedging efficiency of weather-indexed insurance for corn production in Northeast of China. The purpose of this paper is to identify the potential…

Abstract

Purpose

The paper analyzes the hedging efficiency of weather-indexed insurance for corn production in Northeast of China. The purpose of this paper is to identify the potential weather variables that impact corn yields and to analyze the efficiency of weather-indexed insurance under varying thresholds for payouts (strike values).

Design/methodology/approach

Statistical relationships between climate variables and crop yields are used to construct weather-indexed insurance that enable a farmer to hedge against adverse precipitation outcomes. Mean root square loss is used to compare the efficiency of various weather products.

Findings

Based on efficiency comparisons, it turns out that in some, but not all circumstances, cumulative rainfall (CR) insurance can be used to hedge weather risk. When CR explains one-third or more of the variation in corn yields, a hedge can offset the revenue loss caused by the corresponding weather risk; but when it explains much less of the yield variation, it is inefficient for hedgers to buy weather insurance. If CR explains variation in crop yields, it is increasingly efficient to employ CR-indexed insurance as strike values decline for put options or increase for call options.

Practical implications

The paper provides a method for calculating the premium for an insurance product that provides a payout if CR in a growing season is too low.

Originality/value

This research is important because it illustrates the potential benefits of using weather insurance as an agricultural risk management strategy in China.

Details

Agricultural Finance Review, vol. 74 no. 4
Type: Research Article
ISSN: 0002-1466

Keywords

Article
Publication date: 11 May 2010

Shyam Adhikari, Eric J. Belasco and Thomas O. Knight

The purpose of this paper is to examine the spatial components of producer heterogeneity in crop insurance product selection among US corn producers and identifies…

Abstract

Purpose

The purpose of this paper is to examine the spatial components of producer heterogeneity in crop insurance product selection among US corn producers and identifies neighborhood spillover or agent marketing effects in these decisions.

Design/methodology/approach

County‐level insurance and yield data are used to demonstrate that a gradual shift from yield‐based insurance to revenue‐based insurance has spatial patterns. Conventional risk variables such as yield variability, price variability, prevalence of irrigation, other crops, and yield‐price relationships play an important role in this shift and are consistently estimated only when spatial components are included. A spatial random effects model is used to also identify the impact of spatial lag effects, which include neighborhood spillover and agent marketing effects, on the share of corn acres insured with revenue‐based plans vs yield‐based plans.

Findings

Theoretically consistent variables associated with risk are found to significantly influence the choice between crop revenue and yield insurance. Non‐linear parameters identify the region‐specific effects from changes in irrigation, yield price correlation, and the prevalence of corn production on insurance decisions. In addition, spatial components such as the decisions made by nearby producers and marketing drives are also found to influence decisions. These results may demonstrate the relative influence of trusted sources, such as nearby producers and insurance agents, on insurance decisions.

Originality/value

Traditional risk variables are consistently estimated by controlling for spatial heterogeneity. This study also reveals the propensity of producers to rely on the opinions of other producers or agents that they know.

Details

Agricultural Finance Review, vol. 70 no. 1
Type: Research Article
ISSN: 0002-1466

Keywords

Article
Publication date: 29 November 2018

Moshe Szweizer

The purpose of this paper is to extend the studies of commercial property yields by providing a cross-field approach through the implementation of methods used in physics.

Abstract

Purpose

The purpose of this paper is to extend the studies of commercial property yields by providing a cross-field approach through the implementation of methods used in physics.

Design/methodology/approach

Based on the equations used to describe real gases in physics, the commercial property yields are expressed through a model, as a product of two terms. The first term estimates the influence of the income change and investment on yields. The second estimates the yield variation as a function of property size. Additionally, the model combines the macroeconomic and microeconomic components influencing yield adjustment. Calculation of each component involves procedures developed in physics, with the investment volume being linked to the amount of gas and the microeconomic yield being linked to the gas compressibility.

Findings

The model was applied to the Auckland office and industrial markets, both to the historic and current cycle. At the macro-level, it was found that the use of accumulation of investment over a relevant cycle, results in a high data to model correlation. When modelling the yields at the micro-level, a relationship between the outlying properties and the yield softening was observed.

Practical implications

The paper provides an enhanced modelling power through association of the cyclic and investment activity with the yield change. Moreover, the model may be used to decouple the local and the international investment components and the extent of their influence on the local property market. Furthermore, it may be used to estimate the influence of the property size on the yield.

Originality/value

This research provides a new cross-field application of modelling techniques and enhances the understanding of factors influencing yield adjustments.

Details

Journal of Property Investment & Finance, vol. 37 no. 1
Type: Research Article
ISSN: 1463-578X

Keywords

Article
Publication date: 6 November 2009

Christopher A. Wolf, J. Roy Black and Joleen C. Hadrich

The purpose of this paper is to examine the sources and magnitude of variation in accrual adjusted gross farm revenue and farm revenue net of feed purchases on Michigan…

Abstract

Purpose

The purpose of this paper is to examine the sources and magnitude of variation in accrual adjusted gross farm revenue and farm revenue net of feed purchases on Michigan dairy farms representative of Upper Midwest dairy farms. The paper aims to assess whether adjusted gross revenue‐type insurance instruments meet insurability conditions when applied to dairy farms.

Design/methodology/approach

Accrual adjusted dairy farm revenue and revenue net of feed purchased from Michigan dairy farm panel data from 1995 through 2006 were detrended and summarized. Variance decomposition was used to identify sources of variation in adjusted gross revenue and adjusted gross revenue less feed purchases. In‐sample insurance premiums were estimated and Monte Carlo simulations were used to adjust these premiums for out‐of‐sample considerations.

Findings

Milk price variation was the largest source of variation while milk production per cow varied little. Farms with smaller herds and those with larger percentages of farm revenue from crop sales had higher relative revenue variability and would trigger a higher frequency of indemnities under a whole farm revenue insurance contract.

Research limitations/implications

Because the data analyzed conclude in 2006, the volatility of the past couple of years is not reflected. Therefore, researchers are encouraged to test the proposed insurance feasibility further with more recent data.

Practical implications

The paper addresses considerations for the development and commercialization of a feasible dairy revenue insurance instrument.

Originality/value

This paper fulfils a need to understand magnitude and source of revenue variation on dairy farms and how insurance might mitigate negative consequences of this variation.

Details

Agricultural Finance Review, vol. 69 no. 3
Type: Research Article
ISSN: 0002-1466

Keywords

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