scholarly journals Revenue Insurance for Georgia and South Carolina Peaches

2000 ◽  
Vol 32 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Stephen E. Miller ◽  
Kandice H. Kahl ◽  
P. James Rathwell
Keyword(s):  
South Carolina ◽  
High Coverage ◽  
Premium Rate ◽  
Revenue Insurance ◽  
Statistical Sense ◽  
The Mean ◽  
Premium Rates ◽  
Insurance Rates ◽  
High Yields ◽  
Yield Insurance

AbstractWe estimate actuarially fair premium rates for yield and revenue insurance for Georgia and South Carolina peaches. The premium rates for both products decrease at a decreasing rate as the mean farm-level yield increases. In general, the premium rate for revenue insurance exceeds the premium rate for yield insurance for a given coverage level and expected yield. Although the revenue and yield insurance rates differ in a statistical sense, they do not appear to differ in an economic sense except at high coverage levels for growers with very high yields.

scholarly journals Estimating Crop Yield Insurance Premium Rates

1984 ◽  
Vol 13 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Daniel J. Dudek ◽  
P. Geoffrey Allen
Keyword(s):  
Adverse Selection ◽  
Crop Yield ◽  
Technical Change ◽  
Calculation Method ◽  
Insurance Premium ◽  
Premium Calculation ◽  
Premium Rates ◽  
Insurance Rates ◽  
Definition Of ◽  
Yield Insurance

Insurance rates for crop yield protection programs have traditionally been calculated from county average yields. Where grower acreages and yields are not homogeneous, this approach leads to higher premiums and payouts and greater incidence of adverse selection. With individual grower data a production weighted rate premium calculation method can be used which avoids these problems. Furthermore, the definition of rate classes is not constrained to county boundaries. The additional complication of technical change is addressed and one solution is provided. Results are presented for the cranberry industry.

The effects of overconfident yield forecasting on cross-coverage level crop insurance demand

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Clayton P. Michaud
Keyword(s):  
Crop Insurance ◽  
Insurance Coverage ◽  
Coverage Level ◽  
Insurance Demand ◽  
Management Tools ◽  
Content Type ◽  
Revenue Insurance ◽  
Yield Risk ◽  
Yield Forecasting ◽  
Yield Insurance

PurposeThis paper examines the effect of overconfident yield forecasting (optimism bias) on crop insurance coverage level choices across both yield and revenue insurance.Design/methodology/approachThis study simulates a representative producer’s preferred coverage level for both yield and revenue insurance under three potential models of decision-making and four potential manifestations of overconfident yield forecasting. The study then uses this framework to examine how coverage level choices change as overconfidence increases (decreases).FindingsAs overconfidence increases, producers prefer lower levels of crop insurance coverage than they would otherwise prefer, with extreme overconfidence inducing farmers to buy no insurance at all. While overconfidence affects cross-coverage demand for revenue and yield insurance similarly, this effect is more pronounced for yield insurance. Cross-coverage level demand for revenue insurance is relatively stable across changes in the correlation between prices and yields.Practical implicationsThis research has important implications for crop insurance subsidy design and crop insurance demand modeling.Originality/valueThere is a growing body of literature suggesting that producers are overconfident with regard to their future yield risk and that this bias reduces their willingness to pay for risk management tools such as crop insurance. This is the first study to look at how such overconfidence affects cross-coverage level demand for crop insurance.

Note on Determination of Premium Rates for Motor Vehicles (Third Party Risks) Insurance in New Zealand

1972 ◽  
Vol 98 (2) ◽  
pp. 149-156
Author(s):  
J. E. Eriksen ◽  
E. J. Jones
Keyword(s):  
New Zealand ◽  
Life Insurance ◽  
Motor Vehicle ◽  
Third Party ◽  
Motor Vehicles ◽  
Motor Insurance ◽  
Premium Rates ◽  
Insurance Rates ◽  
Basic Ideas

The authors have advised on the level of motor vehicle (third party risks) insurance rates of premium in the circumstances under which that business is written in New Zealand and this paper records the approach taken. It has been prepared in the hope that, as no difficult mathematics are involved, the basic ideas may appeal both to actuaries and to persons other than actuaries who are interested in the transaction of non-life insurance. They are relevant not merely to third party motor insurance but also to non-life insurance generally in a situation where insurance is compulsory and the rates of premium are centrally controlled. In those circumstances more sophisticated techniques of deriving premium rates are less necessary.

scholarly journals Resistance to Benzimidazole and Dicarboximide Fungicides in Greenhouse Isolates of Botrytis cinerea

Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 569-575 ◽  
Author(s):  
L. F. Yourman ◽  
S. N. Jeffers
Keyword(s):  
South Carolina ◽  
Botrytis Cinerea ◽  
Active Ingredient ◽  
Disease Incidence ◽  
Correlation Coefficients ◽  
Effective Concentration ◽  
Mycelium Growth ◽  
Thiophanate Methyl ◽  
Conidium Germination ◽  
The Mean

In 1996 and 1997, 325 isolates of Botrytis cinerea were collected from 35 commercial greenhouses growing ornamental crops in South Carolina to determine the incidence of resistance to benzimidazole and dicarboximide fungicides. Conidium germination was assessed on a defined agar medium amended with either thiophanate-methyl (a benzimidazole) or vinclozolin (a di-carboximide). A total of 53 representative isolates were evaluated further for conidium germination and mycelium growth on fungicide-amended medium and for infection of geranium seedlings treated with thiophanate-methyl or vinclozolin at label rates. Isolates were considered sensitive to thiophanate-methyl or vinclozolin when the effective concentration of the fungicide active ingredient resulting in 50% inhibition of germination (EC50-germ) was ≤5 μg/ml or when the effective concentration of fungicide active ingredient resulting in 50% inhibition of mycelium growth (EC50-growth) was ≤1 μg/ml. Of all isolates, 81% (262/325) were resistant to thiophanate-methyl and 69% (223/325) were resistant to vinclozolin. Four phenotypes were observed: sensitive to both fungicides (17%), resistant to both fungicides (67%), resistant only to thiophanate-methyl (14%), and resistant only to vinclozolin (2%). Isolates resistant to at least one fungicide were found in 33 of the 35 locations from which samples were taken. Disease incidences on geranium seedlings treated with 600 μg/ml of thiophanate-methyl and then inoculated with isolates sensitive and resistant to this fungicide were 1.4 and 96.1%, respectively. Disease incidences on geranium seedlings treated with 600 μg/ml of vinclozolin and then inoculated with isolates sensitive and resistant to this fungicide were 0.3 and 91.9%, respectively. With thiophanate-methyl, correlation coefficients (r) between disease incidence and log EC50-germ or log EC50-growth were 0.987 and 0.992, respectively. With vinclozolin, correlation coefficients between disease incidence and log EC50-germ and log EC50-growth were 0.975 and 0.893, respectively. Correlation coefficients between the two EC50 values for thiophanate-methyl were 0.989 and for vinclozolin were 0.900. Isolates sensitive to thiophanate-methyl had a mean EC50-germ value of 0.93 μg/ml and a EC50-growth value of 0.11 μg/ml. For isolates sensitive to vinclozolin the mean EC50-germ value was 1.63 μg/ml and the mean EC50-growth value was 0.26 μg/ml. Thiophanate-methyl-resistant isolates had mean EC50-germ and EC50-growth values greater than 500 μg/ml while vinclozolin-resistant isolates had a mean EC50-germ value greater than 500 μg/ml and a mean EC50-growth value of 3.18 μg/ml.

scholarly journals Some Problems Connected with the Calculation of Stop Loss Premiums for Large Portfolios

1967 ◽  
Vol 4 (2) ◽  
pp. 170-174 ◽  
Author(s):  
Fredrik Esscher
Keyword(s):  
Distribution Function ◽  
Expected Number ◽  
Limit Values ◽  
Empirical Determination ◽  
The Mean ◽  
Premium Rates ◽  
Image Position ◽  
Stop Loss ◽  
The Given

When experience is insufficient to permit a direct empirical determination of the premium rates of a Stop Loss Cover, we have to fall back upon mathematical models from the theory of probability—especially the collective theory of risk—and upon such assumptions as may be considered reasonable.The paper deals with some problems connected with such calculations of Stop Loss premiums for a portfolio consisting of non-life insurances. The portfolio was so large that the values of the premium rates and other quantities required could be approximated by their limit values, obtained according to theory when the expected number of claims tends to infinity.The calculations were based on the following assumptions.Let F(x, t) denote the probability that the total amount of claims paid during a given period of time is ≤ x when the expected number of claims during the same period increases from o to t. The net premium II (x, t) for a Stop Loss reinsurance covering the amount by which the total amount of claims paid during this period may exceed x, is defined by the formula and the variance of the amount (z—x) to be paid on account of the Stop Loss Cover, by the formula As to the distribution function F(x, t) it is assumed that wherePn(t) is the probability that n claims have occurred during the given period, when the expected number of claims increases from o to t,V(x) is the distribution function of the claims, giving the conditioned probability that the amount of a claim is ≤ x when it is known that a claim has occurred, andVn*(x) is the nth convolution of the function V(x) with itself.V(x) is supposed to be normalized so that the mean = I.

Escherichia coli flavohaemoglobin (Hmp) with equistoichiometric FAD and haem contents has a low affinity for dioxygen in the absence or presence of nitric oxide

2001 ◽  
Vol 353 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Catherine E. MILLS ◽  
Svetlana SEDELNIKOVA ◽  
Britta SØBALLE ◽  
Martin N. HUGHES ◽  
Robert K. POOLE
Keyword(s):  
Nitric Oxide ◽  
No Reduction ◽  
O2 Consumption ◽  
Purification Procedure ◽  
Turnover Number ◽  
No Removal ◽  
Cell Extracts ◽  
Oxygenase Activity ◽  
The Mean ◽  
High Yields

A purification procedure for flavohaemoglobin Hmp (NO oxygenase) is described that gives high yields of protein with equistoichiometric haem and FAD contents. H2O2 accumulated on NADH oxidation by the purified protein and in cell extracts with elevated Hmp contents. H2O2 probably arose by dismutation from superoxide, which was also detectable during oxygen reduction; water was not a product. In the absence of agents that scavenge superoxide and peroxide, the mean Km for oxygen was 80µM; the addition of 15µM FAD decreased the Km for oxygen to 15µM without a change in Vmax but catalysed cyanide-insensitive oxygen consumption, attributed to electron transfer from flavins to O2. Purified Hmp consumed NO in the absence of added FAD (approx. 1 O2 per NO), which is consistent with NO oxygenation. However, half-maximal rates of NO-stimulated O2 consumption required approx. 47µM O2; NO removal was ineffective at physiologically relevant O2 concentrations (below approx. 30µM O2). On exhaustion of O2, NO was removed by a cyanide-sensitive process attributed to NO reduction, with a turnover number approx. 1% of that for oxygenase activity. These results suggest that the ability of Hmp to detoxify NO might be compromised in hypoxic environments.

scholarly journals Grain Area Yield Index Insurance Ratemaking Based on Time–Space Risk Adjustment in China

2020 ◽  
Vol 12 (6) ◽  
pp. 2491 ◽  
Author(s):  
Xiaotao Li ◽  
Jinzheng Ren ◽  
Beibei Niu ◽  
Haiping Wu
Keyword(s):  
Risk Adjustment ◽  
Index Insurance ◽  
Time Varying ◽  
Agricultural Insurance ◽  
Premium Rate ◽  
Model Based ◽  
Time Space ◽  
Pure Premium ◽  
Premium Rates ◽  
The Impact

The foundation and sustainable development of agricultural insurance involve accurately determining a premium and establishing a dynamic premium adjustment mechanism that matches the agricultural production risk. Based on the theoretical analysis of the impact of time–space risk adjustment on agricultural insurance ratemaking, we constructed a pure premium ratemaking model based on time-varying risk adjustment and a safety premium ratemaking model based on spatially dependent risk adjustment. Choosing the county grain area-yield index insurance (GAYI) in China as the research object, we obtained the following results: (1) the risk of grain yield per unit area (YPUA) and pure premium rate in most counties decreased significantly with time-varying adjustment, and we observed differences between regions; (2) grain’s spatially dependent risk has a strong negative adjustment effect on the loading factor, but the expansion of insurance underwriting can still rapidly reduce the safety premium rate, mainly due to the reduction in the spatially dependent risk; and (3) based on time-varying risk adjustment and underwriting expansion, the reduction effect of premium rates is obvious, which supports the sustainable commercial operation of agricultural insurance. These research results help to clarify the relationships of premium rates and provide implications on the sustainability of catastrophe management.

Effect of gypsum and deep ripping on lucerne (Medicago sativa L.) yields on a red-brown earth under flood and spray irrigation

1987 ◽  
Vol 27 (6) ◽  
pp. 841 ◽  
Author(s):  
AJ Taylor ◽  
KA Olsson
Keyword(s):  
Field Experiments ◽  
Flood Irrigation ◽  
Physico Chemical ◽  
Full Production ◽  
Additional Water ◽  
Spray Irrigation ◽  
Medicago Sativa L ◽  
The Mean ◽  
High Yields ◽  
Soil Responses

Lucerne yield and soil responses to gypsum and deep ripping treatments were studied under flood and spray irrigation on 2 field experiments on a heavy red-brown earth. One application of gypsum at 12 t ha-1, both alone (G) and in combination with ripping to 0.6 m depth (GR) before sowing, resulted in sustained high yields of lucerne during a 4- year experiment. Under flood irrigation. there was no apparent yield advantage of GR treatments over G alone; yields averaged over 3 full production years were 143 and 175 t ha-1 for the control and the mean of the G and GR treatments, respectively. However, under spray irrigation, the mean annual hay yields for the control, G and GR treatments of 12.6, 17.3 and 19.4 t ha-1, respectively, were significantly different (P = 0.05). Yield was increased in proportion to the additional water made available to the crop resulting from deeper wetting of the ameliorated soils at irrigation. Increased water intake was attributed to increased conductance of the B horizon for water due to gypsum and/or deep ripping. Under flood irrigation. macroporosities measured at 0.30 m depth 4 years after treatment were higher in the ameliorated soils than the control but were no different between the G and GR treatments. In the spray experiment, the GR soils had consistently higher porosities and lower bulk densities than the G soils; the latter were no different to the control in these properties. The increased conductance is attributed to reduced clay swelling and the increased macroporosity of the B horizon due to ripping. Where measured on the flood experiment, the GR treatment promoted root growth in the R horizon. The longer-term stability of the ameliorated soils is discussed in relation to physico-chemical and biological mechanisms.

scholarly journals Variance in Estimated Pairwise Genetic Distance Under High versus Low Coverage Sequencing: the Contribution of Linkage Disequilibrium

2017 ◽  
Author(s):  
Max Shpak ◽  
Yang Ni ◽  
Jie Lu ◽  
Peter Müller
Keyword(s):  
Linkage Disequilibrium ◽  
Genetic Distance ◽  
Low Frequency ◽  
Allele Frequencies ◽  
High Coverage ◽  
Pairwise Linkage Disequilibrium ◽  
Pairwise Genetic Distance ◽  
Linkage Disequilibria ◽  
The Mean ◽  
Low Coverage

AbstractThe mean pairwise genetic distance among haplotypes is an estimator of the population mutation rate θ and a standard measure of variation in a population. With the advent of next-generation sequencing (NGS) methods, this and other population parameters can be estimated under different modes of sampling. One approach is to sequence individual genomes with high coverage, and to calculate genetic distance over all sample pairs. The second approach, typically used for microbial samples or for tumor cells, is sequencing a large number of pooled genomes with very low individual coverage. With low coverage, pairwise genetic distances are calculated across independently sampled sites rather than across individual genomes. In this study, we show that the variance in genetic distance estimates is reduced with low coverage sampling if the mean pairwise linkage disequilibrium weighted by allele frequencies is positive. Practically, this means that if on average the most frequent alleles over pairs of loci are in positive linkage disequilibrium, low coverage sequencing results in improved estimates of θ, assuming similar per-site read depths. We show that this result holds under the expected distribution of allele frequencies and linkage disequilibria for an infinite sites model at mutation-drift equilibrium. From simulations, we find that the conditions for reduced variance only fail to hold in cases where variant alleles are few and at very low frequency. These results are applied to haplotype frequencies from a lung cancer tumor to compute the weighted linkage disequilibria and the expected error in estimated genetic distance using high versus low coverage.

scholarly journals Research on Revenue Insurance Premium Ratemaking of Jujube Based on Copula-Stochastic Optimization Model

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Li-Mei Qi ◽  
Ruo-Yu Yao ◽  
Xing-Zhe Zhang ◽  
Yu-Jing Zhang ◽  
Xiao-Yin Wang ◽  
...  
Keyword(s):  
Stochastic Optimization ◽  
Optimization Model ◽  
Unit Area ◽  
Copula Function ◽  
Insurance Premium ◽  
Distribution Functions ◽  
Risk Minimization ◽  
Premium Rate ◽  
Empirical Copula ◽  
Revenue Insurance

During the process of jujube planting, there are not only natural risks caused by natural disasters but also market risks caused by price factors. In the study, firstly, wavelet analysis method was used to stabilize the jujube yield per unit area and the jujube price from 1997 to 2018 in Aksu region, Xinjiang, China. Secondly, EasyFit software was used to fit the distribution functions of yield per unit area and price, respectively. Thirdly, the optimal Copula function which connects the marginal distribution functions and its joint distribution function was selected with the principle of “the minimum square distance from the empirical Copula function.” Finally, taking the premium rate and the insurance amount as two decision variables, the farmer’s risk minimization as the objective function, around the four constraints of functions and role of insurance, the nonspeculative nature of insurance, the sustainability of insurance, and the moral hazard factors and the farmers’ willing to participate in insurance, the Copula-stochastic optimization model was set up to determine the premium rate of jujube revenue insurance in Aksu region.

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