Agriculture as the Potential Engine for African Growth and the Role of NEPAD

Landwirtschaftliche Entwicklung; Entwicklungskooperation; Wirtschaftswachstum; Afrika

Pseudo-R2 Measures for Some Common Limited Dependent Variable Models

A large number of different Pseudo-R2 measures for some common limited dependent variable models are surveyed. Measures include those based solely on the maximized likelihoods with and without the restriction that slope coefficients are zero, those which require further calculations based on parameter estimates of the coefficients and variances and those that are based solely on whether the qualitative predictions of the model are correct or not. The theme of the survey is that while there is no obvious criterion for choosing which Pseudo-R2 to use, if the estimation is in the context of an underlying latent dependent variable model, a case can be made for basing the choice on the strength of the numerical relationship to the OLS-R2 in the latent dependent variable. As such an OLS-R2 can be known in a Monte Carlo simulation, we summarize Monte Carlo results for some important latent dependent variable models (binary probit, ordinal probit and Tobit) and find that a Pseudo-R2 measure due to McKelvey and Zavoina scores consistently well under our criterion. We also very briefly discuss Pseudo-R2 measures for count data, for duration models and for prediction-realization tables

Celebrating 150 Years of Analyzing Fertility Trends in Germany

Ever since the very beginning of the Journal of Economics and Statistics, population economics has featured prominently in the Journal. Fertility naturally plays an important role in population economics. Its size has decreased significantly from the 1900s. Long time-series regarding fertility and basic trends in Germany are documented and analyzed. We identify three different explanatory approaches for the decline in fertility, according to which the various articles of the Journal related to this area are categorized. The paper also investigates previous fertility studies published by the Journal since the beginning. It points out that several articles anticipated subsequent research directions in the area of population economics at an early stage. In addition, significant contributions were made in terms of further developing existing knowledge. Thus, the Journal has helped to expand the research area of population economics.self-regulation, Malthus, total fertility rate, fertility, Q-Q trade-off

Reconsidering the syntax of interrogatives in Caribbean Spanish, with special reference to Dominican Spanish

This paper readdresses one of the most conspicuous syntactic traits of varieties of Caribbean Spanish that has been on the research agenda ever since its detection almost a hundred years ago: the preverbal occurrence of subjects in interrogatives with a simple non-subject argumental wh-expression. In an attempt to shed more light on the still highly controversial issues of the frequency of whSV order and the kind(s) of preverbal subject, the paper initially gathers relevant claims as well as examples from the literature and then presents pertinent results from a refined large-scale quantitative analysis of natural speech from colloquial Dominican Spanish, hereby filling a long-standing lacuna. Additionally, the paper discusses previous approaches, showing that none of these are free from problems. Drawing on relevant aspects of earlier approaches and building on insights into the fairly related state of affairs in medieval French, the paper eventually argues that whSV order in Dominican, and by extension, other pertinent varieties of Caribbean Spanish, follows from ongoing morpho-syntactic changes that are taken to ultimately result in the resetting of the null subject parameter: the development of a paradigm of weak subject pronouns, the concomitant establishment of a dedicated subject position, SpecTP, and the overall strong tendency towards SV order

Foreword

In this book, an international team of fourteen scholars investigates the Chinese reception of Indian Buddhist ideas, especially in the sixth and seventh centuries. Topics include Buddhist logic and epistemology (pramāṇa, yinming); commentaries on Indian Buddhist texts; Chinese readings of systems as diverse as Madhyamaka, Yogācāra and tathāgatagarbha; the working out of Indian concepts and problematics in new Chinese works; and previously under-studied Chinese evidence for developments in India. The authors aim to consider the ways that these Chinese materials might furnish evidence of broader Buddhist trends, thereby problematizing a prevalent notion of “sinification”, which has led scholars to consider such materials predominantly in terms of trends ostensibly distinctive to China. The volume also tries to go beyond seeing sixth- and seventh-century China primarily as the age of the formation and establishment of the Chinese Buddhist “schools”. The authors attempt to view the ideas under study on their own terms, as valid Buddhist ideas engendered in a rich, “liminal” space of interchange between two large traditions.In this book, an international team of fourteen scholars investigates the Chinese reception of Indian Buddhist ideas, especially in the sixth and seventh centuries. Topics include Buddhist logic and epistemology (pramāṇa, yinming); commentaries on Indian Buddhist texts; Chinese readings of systems as diverse as Madhyamaka, Yogācāra and tathāgatagarbha; the working out of Indian concepts and problematics in new Chinese works; and previously under-studied Chinese evidence for developments in India. The authors aim to consider the ways that these Chinese materials might furnish evidence of broader Buddhist trends, thereby problematizing a prevalent notion of “sinification”, which has led scholars to consider such materials predominantly in terms of trends ostensibly distinctive to China. The volume also tries to go beyond seeing sixth- and seventh-century China primarily as the age of the formation and establishment of the Chinese Buddhist “schools”. The authors attempt to view the ideas under study on their own terms, as valid Buddhist ideas engendered in a rich, “liminal” space of interchange between two large traditions

Transition from connected to fragmented vegetation across an environmental gradient: scaling laws in ecotone geometry

A change in the environmental conditions across space—for example, altitude or latitude—can cause significant changes in the density of a vegetation type and, consequently, in spatial connectivity. We use spatially explicit simulations to study the transition from connected to fragmented vegetation. A static (gradient percolation) model is compared to dynamic (gradient contact process) models. Connectivity is characterized from the perspective of various species that use this vegetation type for habitat and differ in dispersal or migration range, that is, “step length” across the landscape. The boundary of connected vegetation delineated by a particular step length is termed the “ hull edge.” We found that for every step length and for every gradient, the hull edge is a fractal with dimension 7/4. The result is the same for different spatial models, suggesting that there are universal laws in ecotone geometry. To demonstrate that the model is applicable to real data, a hull edge of fractal dimension 7/4 is shown on a satellite image of a piñon‐juniper woodland on a hillside. We propose to use the hull edge to define the boundary of a vegetation type unambiguously. This offers a new tool for detecting a shift of the boundary due to a climate change

Symposium on ‘Geographical and geological influences on nutrition' Iodine deficiency in industrialised countries: Conference on ‘Over- and undernutrition: challenges and approaches'

Iodine deficiency is not only a problem in developing regions; it also affects many industrialised countries. Globally, two billion individuals have an insufficient iodine intake, and approximately 50% of continental Europe remains mildly iodine deficient. Iodine intakes in other industrialised countries, including the USA and Australia, have fallen in recent years. Iodine deficiency has reappeared in Australia, as a result of declining iodine residues in milk products because of decreased iodophor use by the dairy industry. In the USA, although the general population is iodine sufficient, it is uncertain whether iodine intakes are adequate in pregnancy, which has led to calls for iodine supplementation. The few available data suggest that pregnant women in the Republic of Ireland and the UK are now mildly iodine deficient, possibly as a result of reduced use of iodophors by the dairy industry, as observed in Australia. Representative data on iodine status in children and pregnant women in the UK are urgently needed to inform health policy. In most industrialised countries the best strategy to control iodine deficiency is carefully-monitored salt iodisation. However, because approximately 90% of salt consumption in industrialised countries is from purchased processed foods, the iodisation of household salt only will not supply adequate iodine. Thus, in order to successfully control iodine deficiency in industrialised countries it is critical that the food industry use iodised salt. The current push to reduce salt consumption to prevent chronic diseases and the policy of salt iodisation to eliminate iodine deficiency do not conflict; iodisation methods can fortify salt to provide recommended iodine intakes even if per capita salt intakes are reduced to <5 g/

Methods to assess iron and iodine status

Four methods are recommended for assessment of iodine nutrition: urinary iodine concentration, the goitre rate, and blood concentrations of thyroid stimulating hormone and thyroglobulin. These indicators are complementary, in that urinary iodine is a sensitive indicator of recent iodine intake (days) and thyroglobulin shows an intermediate response (weeks to months), whereas changes in the goitre rate reflect long-term iodine nutrition (months to years). Spot urinary iodine concentrations are highly variable from day-to-day and should not be used to classify iodine status of individuals. International reference criteria for thyroid volume in children have recently been published and can be used for identifying even small goitres using thyroid ultrasound. Recent development of a dried blood spot thyroglobulin assay makes sample collection practical even in remote areas. Thyroid stimulating hormone is a useful indicator of iodine nutrition in the newborn, but not in other age groups. For assessing iron status, haemoglobin measurement alone has low specificity and sensitivity. Serum ferritin remains the best indicator of iron stores in the absence of inflammation. Measures of iron-deficient erythropoiesis include transferrin iron saturation and erythrocyte zinc protoporphyrin, but these often do not distinguish anaemia due to iron deficiency from the anaemia of chronic disease. The serum transferrin receptor is useful in this setting, but the assay requires standardization. In the absence of inflammation, a sensitive method to assess iron status is to combine the use of serum ferritin as a measure of iron stores and the serum transferrin receptor as a measure of tissue iron deficienc

The impact of iodised salt or iodine supplements on iodine status during pregnancy, lactation and infancy

Objectives: Monitoring of iodine status during pregnancy, lactation and infancy is difficult as there are no established reference criteria for urinary iodine concentration (UI) for these groups; so it is uncertain whether iodized salt programs meet the needs of these life stages. Design and Subjects: The method used in this paper was: 1) to estimate the median UI concentration that reflects adequate iodine intake during these life stages; and 2) to use these estimates in a review of the literature to assess whether salt iodisation can control iodine deficiency in pregnant and lactating women, and their infants. Results: For pregnancy, recommended mean daily iodine intakes of 220-250 μg were estimated to correspond to a median UI concentration of about 150 μg l−1, and larger surveys from the iodine sufficient countries have reported a median UI in pregnant women ≥140 μg l−1. Iodine supplementation in pregnant women who are mild-to-moderately iodine deficient is beneficial, but there is no clear affect on maternal or newborn thyroid hormone levels. In countries where the iodine intake is sufficient, most mothers have median breast milk iodine concentration (BMIC) greater than the concentration (100-120 μg l−1) required to meet an infant's needs. The median UI concentration during infancy that indicates optimal iodine nutrition is estimated to be ≥100 μg l−1. In iodine-sufficient countries, the median UI concentration in infants ranges from 90-170 μg l−1, suggesting adequate iodine intake in infancy. Conclusions: These findings suggest pregnant and lactating women and their infants in countries with successful sustained iodised salt programs have adequate iodine statu