Data Aggregation Issues for Crop Yield Risk Analysis

With increased emphasis on risk management in agriculture and a lack of disaggregated or farm‐level yield time series, decision makers are often faced with having to make adjustments to temporal yield risk measures obtained from readily available but aggregated yield data. This paper provides some empirical evidence on what type of aggregation bias to expect when measuring temporal yield risk using yield observations averaged across a region relative to yield risk estimated from quarter‐section yield time series in wheat. This study highlights some of the challenges faced when estimating aggregation distortions in measuring yield risk defined by temporal variance, especially given the nature of the empirical data set used. Cluster analysis, visual examination of relative frequency distributions and mapping of yield risk clusters suggest that using a readily available, aggregate temporal yield risk measure has the tendency to underestimate yield risk observed at the quarter‐section level and that clear, geographic yield risk boundaries do not exist in municipalities or across larger areas in this study. Further research on crops more risky than wheat appears promising. Avec un plus grand intéret sur la gestion du risk dans l'agriculture et un manque de données détaillees ou bien de collections de séries temporelles sur les rendements, les décideurs sont souvent tenus d'apporter des correctifs aux measures du risk obtenues a partir des données de rendements qui sont disponibles. Cet artcle apporte une preuve empirique du type de biais lie a l'agrégation qui peut être présent dans le calcul du risk de rendement temporel obtenu a partir de rendements moyens de blé observés au niveau régional en comparaison du risk de rendement qui est estimé a partir de données basées sur des quart‐de‐sections. Cette étude met en exergue quelques uns des obstacles qui se présentent dans l'estimation de distosions liées a l'aggrégation dans le calcul du risk de rendement défini par la variance temporelle, speciallement étant donne la charactère empirique des données utilisées. L'analyse de groupe, l'examen visual de la distribution des fréquences relatives, et la cartographie de classes de risk de rendement suggèrent que l'utilisation de la measure du risk de rendement basée sur des données disponibles de risk aggrège temporel a tendence a sousestimer le risk de rendement observe au niveau des quart‐de‐sections et qu'il n'y a pas de frontières de risk de rendement certaines, géographiques qui existent entre les municipalités ou bien a travers les zones plus larges examinées dans cette etude.     

On the shape of the single-country and world commodity-substitution and factor-substitution surfaces under conditions of joint production

In recent years trade theorists have completed the task of specifying necessary and sufficient conditions for the single-country and world transformation surfaces to be locally of any assigned degree of flatness. However those conditions are relevant only if the technology is of the no-joint-products type. In the present note we derive necessary and sufficient conditions for the single-country and world transformation surfaces to be of any assigned degree of flatness under conditions of joint production; and we also obtain, as a by-product, necessary and sufficient conditions for the single-country and world equal-product surfaces to be of any assigned degree of flatness.     

THE EFFECT OF MINIMUM WAGES ON UK AGRICULTURE

Since the abolition of the Wages Councils in September 1993, agriculture is the only sector in the UK economy covered by any form of minimum wage legislation. However, the recent denunciation of an ILO convention covering minimum wages in agriculture has paved the way for the abolition of the Agricultural Wages Boards. This paper investigates the impact of the system of minimum wages on the level and structure of earnings and employment in agriculture. On wages, our main conclusion is that the minimum wages set by the Agricultural Wages Boards are important determinants of the average level and distribution of earnings in UK agriculture. On employment, our main conclusion is that there is no evidence that minimum wages have reduced the level of employment in agriculture. If anything, our estimates imply a weak positive, though statistically insignificant, impact of minimum wages on employment. This seems to be true when we disaggregate by sex and skill.     

The relationship between risk experience and risk response: a study of farmers and climate change

Within the existing literature, the role of experience of risk on attitudinal and behavioural risk response has been relatively neglected. Recent research that draws on the psychological distance of climate change as a concept notes the importance of local, significant experience as a driver for encouraging appropriate response. The experience of flooding was used as the stimulus in this paper, and emphasis placed on whether direct and/or indirect experience of flood risk is associated with different responses to climate change risk. In order to explore the relationship between climate change risk experience and response in the form of on-farm mitigation and adaptation, this paper draws on a case study of farmers in England, many of whom have experienced flooding. Results from a quantitative survey undertaken with 200 farmers in Gloucestershire, England are discussed. Statistical analysis found experience of flooding to be significantly associated with a heightened concern for climate change. Although also finding an association between experience and behavioural response, the sample were most likely to be taking adaptive behaviour as part of normal practice, with factors such as lack of overall concern for climate change risk and absence of information and advice likely to be the main barriers to action. Risk communication needs to further emphasise the connection between climate change and extreme weather events to allow for farmers to perceive climate change as a relevant and locally salient phenomenon, and subsequent tailored information and advice should be offered to clearly illustrate the best means of on-farm response. Where possible, emphasis must be placed on actions that also enable adaptation to other, more immediate risks which farmers in this study more readily exhibited concern for, such as market volatility.     

Explaining intercity home price differences

This paper develops and tests an equilibrium model seeking to explain intercity variation in owner-occupied housing prices. Empirical tests with a reduced form equation using aggregated 1980 data on 94 SMSAs suggest explanation for 84% of this intercity home price variation. Intercity housing demand, based upon homeowner quality of life equilibrium, is successfully represented by the non-monetary income determinant of climate mildness in addition to several monetary income determinants that reflect household residual after-tax real income. Intercity housing supply was found to be influenced by intercity variation in construction costs and limitations upon the available supply of undeveloped urban land.     

Beyond radical affordability in the base of the pyramid: The role of consumer self-confidence in product acceptance

When developing products and services for base of the economic pyramid (BoP) consumers, it has been widely assumed that organizations must set extremely low prices that are dependent on substantial product acceptance and economies of scale. However, such pricing is often not feasible. Growing evidence suggests that more moderate price levels are needed for organizations to viably serve the needs of low-income consumers. However, price sensitivity is less understood in low-income contexts. To promote the success of social enterprises through fresh insight, we reexamine the extremely low-price BoP assumption by investigating product acceptance among low-income consumers using two experiments in Latin America. Results reveal that a belief in one's capabilities to make effective consumption decisions, consumer self-confidence, helps explain the acceptance of moderately-priced products. Discussion highlights directions for stimulating acceptance of socially beneficial products in low-income contexts.