Decision-making Criteria for Purchasing Milk Quota at the Individual Farm Level: A Comment

In a recent article in this journal, Stonehouse and MacGregor outlined several elements of the farm level decision to purchase milk quota. They provide a useful reminder that, because quota is an asset, decisions regarding its purchase or sale should be undertaken and analyzed with capital budgeting techniques. More specifically, they describe procedures for calculating the net flow return from additional quota under different cost circumstances and the subsequent bid price which that farm could pay for the quota asset. It is the purpose of this comment to show that errors of both commission and omission have found their way into the paper. In addition, there is a problem of inconsistency because the text and the actual calculation formulae are sometimes contradictory.     

AN APPROACH TO THE ECONOMETRIC ESTIMATION OF ATTITUDES TO RISK IN AGRICULTURE: COMMENT

Bardsley and Harris (1987) test empirically the effects of changes In deterministic wealth and random income on the measure partial risk aversion. The paper, which is otherwise well written, failed to impose the relationship between the two effects and estimated them independently. Consequently, inconsistent estimates were derived for the elasticities of the measure of partial risk aversion with respect to wealth and to income. The purpose of this comment is to derive that relationship theoretically and to point out the resulting inconsistencies in the original paper.     

The Demand for Atlantic Salmon in Canada: Reply

In their comment on our paper, Bing-Hwan Lin and Nancy Williams have raised some interesting issues, but some of them are peripheral to the objective of our original study. The central objective of our original paper is to estimate income and price elasticities of demand for Atlantic salmon in Canada and then to use the parameter values to evaluate the market potential of farmed Atlantic salmon which are now being produced in Atlantic Canada. Accordingly, a demand equation has been estimated using annual data for the period 1955–1981. The inverted form has given a good fit and the results are reported in the paper.     

Including Imperfect Competition in Spatial Equilibrium Models

Following Martin's paper on quadratic spatial equilibrium models this paper presents ways to incorporate imperfect competition in these models by altering the objective function of the quadratic program. This paper shows how the standard Cournot and Slackelberg equilibria may be modelled. The paper also describes the new theoretical models of consistent conjectural variations and how they may be translated into quadratic spatial equilibrium models. Situations that are likely to be modelled are discussed and appropriate models are presented. More complicated equilibria that cannot be modelled by simple adjustment of the quadratic objective function are also discussed.
Aprés la composition de Martin sur les modeles de L'équilibre quadratique et spatial, nous presentons des moyens d'incorprer la compétition imparfaite dans ces modeles en modifiant la fonction objective du programe quadratique. Nous montrons comment on peut modeler les équilibres Cournot et Stackelberg. Nous décrivons aussi les nouveaux modeles théoriques des variations consistentes et conjecturales, et comment ils peuvent éytre traduits en modeles de l'équilibre quadratique et spatial. Nous discutons les situations qui peuvent probablement étre modelées et nous presentons des modeles qui nous semblent appropriés. Nous discutons aussi des équilibres plus compliqués qui ne peuvent pas étre modelés par un simple ajustement de la fonction objective et quadratique.     

Gendered impacts of fertilizer subsidy removal programs in Malawi and Cameroon

Gladwin's^** main contention is that women provide most of the agricultural labor in sub-Saharan Africa and because much of this labor is oriented to food production for home consumption, the effects of structural adjustment programs on them and the children they work to feed are likely to be different than on men who produce crops for commercial and export production. Her specific hypothesis for Malawi is that the removal of the fertilizer subsidy affects women farmers more than men farmers because it reduces fertilizer use on local maize. As part of the structural adjustment program, a major purpose of removing the fertilizer subsidy is to reallocate resources from food production for domestic consumption to cash crop production for export. In Gladwin's analysis, men farmers produce hybrid maize and tobacco for export and women produce the subsistence food crop, local maize. Gladwin's main contention is probably correct. For the Malawi case, the presentation does not support the hypothesis because two of the major underlying assumptions are inappropriate and the evidence provided is inconclusive. This comment proceeds by discussing the two assumptions and corresponding evidence. The purpose of this comment is not to contradict the hypothesis, but to clarify the Malawi situation and to suggest that a different analytical approach is needed in that context.     

Slippage in the Conservation Reserve Program or Spurious Correlation? A Rejoinder

The Conservation Reserve Program (CRP) pays farmers about $2 billion per year to retire cropland under ten- to fifteen-year contracts. Recent research by Wu (2000) found that slippage—an unintended stimulus of new plantings—offsets some of CRP's environmental benefits. In a comment on Wu, we argued CRP enrollments were endogenous and confounded by omitted variables. In his reply, Wu (2005) used results from a Hausman test to argue that CRP enrollments are exogenous. In this rejoinder, we explain why the candidate instrument (erodibility) is likely confounded by omitted variables, so Wu's use of the Hausman test is uninformative.     

The rise of the ‘food charter’: A mechanism to increase urban agriculture

Urban agriculture (UA) is rapidly growing in popularity and significance across the Western hemisphere. For over two decades North Americans have embraced the concept, although in Europe the idea of UA has only recently gained attention from academics, practitioners and policy makers. Networks are beginning to form in the UK, sometimes bound by a ‘food charter’: a statement of aims which bring together businesses, practitioners and other bodies involved or interested in sustainable food systems. More recently, food charters have become popular tools for pursuing the UA agenda. In this paper we provide a view on this method of moving forward the local food agenda; primarily using a case study of Birmingham, we comment on its success and potential for the future.     

The Relationship between Exports, Credit Risk and Credit Guarantees

This paper provides an understanding of how the export credit worthiness of an importing country affects export sales of agricultural and other manufactured products and how export credit guarantees or insurance can mitigate risks of nonpayment. A theoretical model is developed. It shows how risk mitigation through export credit insurance could increase exports to high-risk importing countries. The key result is that the export response curve is more inelastic in the presence of payment risk, and the effect of insurance is to make the export curve more elastic. Statistical evidence supports this fundamental premise.
Le présent article explique comment la solvabilité d'un pays importateur affecte les ventes de produits agricoles et de produits finis à l'étranger et comment la garantie du crédit à l'exportation ou les assurances atténuent les risques de défaut de paiement. Les auteurs proposent un modèle théorique. Ce dernier illustre comment on pourrait accroûtre les exportations vers les pays à risque élevé en atténuant les risques au moyen d'une assurance du crédit à l'exportation. II en ressort principalement que les exportations suivent une courbe moins élastique quand il y a un risque de défaut de paiement et que cette courbe gagne en élasticité avec une assurance. Les auteurs fournissent des preuves statistiques de ce principe élémentaire.     

Ranking Crop Yield Models: A Comment

This comment discusses key specification issues that may have affected the performance and, therefore, the ranking of parametric models that were compared in a recent AJAE article. A procedure to obtain the most flexible parametric model specification possible, given the particular probability distribution function on which the model is based is presented. These specifications also allow for standardized and, therefore, more valid comparisons across parametric models that are based on different probability distributions. Finally, the comment cautions against generalization of the rankings in that AJAE article and recommends that these more flexible specifications be adopted in future comparisons and applications.     

竞争均衡下的森林外部性以及其经济学意义

根据森林资源的公益性特点论述了森林环境的外部性;以一般均衡理论为基础,建立了导入森林环境外部性时的竞争均衡性路径模型,导出了社会最优化的条件。在此基础上,论述了公共部门对外部性进行干预的经济手段及其政策意义。最后,借助日本森林环境税的实施情况和经验论述了森林环境税在中国实施的现实意义。     

Decision-making Criteria for Purchasing Milk Quota at the Individual Farm Level: Reply

Careful perusal of the comment by Barichello suggests that there are no substantive criticisms of the issues raised in our original paper. At the same time, it is apparent that there is some misinterpretation of the models that we used, and of the assumptions underlying the models. For example, the optimality criterion that marginal cost equals marginal revenue in the earlier models is important in determining whether profits in the enterprise can be increased or decreased. However, the difference between average total costs and average revenue is important in determining the levels of profits and hence the potential rents involved.     

Value of External Reviews of Research at the International Agricultural Research Centers

The Consultative Groups on International Agricultural Research (CGIAR) funds a decentralized system of International Agricultural Research Centers. To monitor the Centers, the CGIAR has instituted a system of program and management reviews. But there is some controversy concerning the proper role, cost, and impact of these reviews. In 1984 we conducted a survey of scientific and administrative staff at the Centers to elicit their perspectives about the benefits and costs of the reviews. We also canvassed the documentation prepared by the external review panels. In this paper we report some of the findings from this study and comment on what we feel is the proper role and scope for external reviews. In particular, we feel that the efficiency of the review process can be improved if external program reviews focus on strategic issues, leaving peer review functions aside. Greater integration should be sought between external reviews and the internal planning arid review mechanisms of the Centers. The successes achieved by this international system of research institutes should lead to considerable confidence about both the system's research and managerial capacity, though not all Centers have achieved uniformly high rates of productivity.     

Comparing states with and without growth management analysis based on indicators with policy implications comment

In a recent volume of this journal, Nelson (Land Use Policy 16 (1999) 121) defines and computes several statewide indicators designed to evaluate the effectiveness of growth management efforts in Oregon and Florida. Two indicators are intended to measure how well states have contained urban sprawl and preserved farmland. They are computed using US Census of Population and US Census of Agriculture data. In this comment, I highlight potential problems associated with using these data to evaluate urban sprawl and farmland preservation, and recompute Nelson's indicators using alternative land use data. Differences and similarities between my indicators and those computed by Nelson are discussed.     

A Comparative Static Analysis of the Welfare Impacts of Supply-Restricting Marketing Boards: Reply

The comment by Harvey and Hubbard (hereafter HH) on our earlier paper concerns the welfare implications of our long-run analysis. They assume a competitive industry where the firms face perfectly elastic supply functions for all factors of production except one. Under such assumptions, they suggest that the area above the long-run supply curve and below a price line can have meaning as a welfare measure. This is in contrast to our paper in which such an area can have no meaning as a welfare measure.     

RESPONDENTS TO CONTINGENT VALUATION SURVEYS: CONSUMERS OR CITIZENS (BLAMEY,COMMON AND QUIGGIN,AJAE 39:3) — A COMMENT

Blarney, Common and Quiggin (1995) (BCQ) suggest that responses to contingent valuation (CV) questionnaires may be framed either according to the extent of individual benefits received, or according to wider views about ethical frameworks, impacts on other people, or desired societal levels. They characterise the individual benefit approach as a consumer model, and responses indicating wider concerns as citizen preferences. Citizen value responses are held to invalidate the economic assumptions underlying the use of CV. Hence, they hypothesize that the incorporation of CV results into benefit-cost analysis is problematic. In this comment we suggest that there are several flaws with the citizen value hypothesis. These can be grouped into arguments about the existence of citizen values based on ethical or altruistic grounds, and arguments about the identification of citizen values.     

Household food consumption in Turkey: a comment

We comment on a recent important article by Akbay et al. anddiscuss some methodological and estimation issues arising fromtheir paper. We then suggest alternative procedures that mayhelp improve their estimates and thereby enhance their usefulnessas a basis for food policy and marketing decisions.     

A COMMENT ON KLIEVE-MACAULAY'S SOUTHERN BLUEFIN TUNA GAME

Klieve and MacAulay (1993) (KM) analyse bargaining between the Australian and Japanese Southern Bluefin Tuna (SBT) industries using game theory. The KM model is a Nash equilibrium with symmetrical information, threat functions and a set of biological constraints. When we attempted to include the New Zealand SBT industry as a player in the KM model, we discovered important shortcomings in it. In this comment, we outline three major shortcomings in the KM model and propose an alternative model of a Nash equilibrium for the SBT industry.     

A Comparative Static Analysis of Welfare Impacts of Supply-Restricting Marketing Boards: A Comnent

Van Kooten and Spriggs (VKS) make a useful contribution to our understanding of the basic theory of the firm as applied to quota restrictions on output, at least as far as their short-run analysis is concerned. However, it is the long-run analysis which is more relevant for judging the welfare implications of the policy, and it is here that the VKS analysis is open to question. This comment puts forth an alternative view. In so doing it also draws attention to some of the more important policy implications of the analysis.     

California conservation Corps: An idea whose time has returned?

The author explains the origins of the California Conservation Corps in the USA. He outlines how, after shaky beginnings, the organization has been the subject of much comment and praise. The activities and achievements of the Californian Conservation Corps are underlined and there is an attempt to explain the factors behind its apparent success. This personal perspective analyses the motivation of the volunteers who constitute this disciplined workforce, faced often with very demanding tasks. Admitting that some factors, possibly unique to California, have favoured this programme, the author considers how adaptation of this approach might have a crucial role in conservation policies.     

FURTHER TOWARDS A MORE DYNAMIC APPROACH TO FARM PLANNING: A COMMENT

In a recent contribution to the Jounal, Harle (1974) introduces a model of the farm firm based on the achievement of what he calls economic technical eficiency. The approach Is an attempt to reconcile recent interpretations of the farm planning problem with the author's own practical experience in farm management. The nature of the planning problem and the definition of economic technical efficiency are of central importance to the validity and usefulness of the model, and both demand further comment.