Forecasting Aggregate Period Specific Birth Rates: The Time Series Properties of a Microdynamic Neoclassical Model of Fertility

This article demonstrates the value of microdata for understanding the effect of wages on life cycle fertility dynamics. Conventional estimates of neoclassical economic fertility models obtained from linear aggregate time series regressions are widely criticized for being nonrobust when adjusted for serial correlation. Moreover, the forecasting power of these aggregative neoclassical models has been shown to be inferior when compared with conventional time series models that assign no role to wages. This article demonstrates, that when neoclassical models of fertility are estimated on microdata using methods that incorporate key demographic restrictions and when they are properly aggregated, they have considerable forecasting power.

The Effect of Expected Income on Individual Migration Decisions

The paper develops a tractable econometric model of optimal migration, focusing on expected income as the main economic influence on migration. The model improves on previous work in two respects: it covers optimal sequences of location decisions (rather than a single once-for-all choice), and it allows for many alternative location choices. The model is estimated using panel data from the NLSY on white males with a high school education. Our main conclusion is that interstate migration decisions are influenced to a substantial extent by income prospects. The results suggest that the link between income and migration decisions is driven both by geographic differences in mean wages and by a tendency to move in search of a better locational match when the income realization in the current location is unfavorable.

Great Mining Camps of Canada 8. The Bathurst Mining Camp, New Brunswick, Part 2: Mining History and Contributions to Society

In the Bathurst Mining Camp (BMC), 12 of the 45 known massive sulphide deposits were mined between 1957 and 2013; one was mined for iron prior to 1950, whereas three others had development work but no production. Eleven of the deposits were mined for base metals for a total production of approximately 179 Mt, with an average grade of 3.12% Pb, 7.91% Zn, 0.47% Cu, and 93.9 g/t Ag. The other deposit was solely mined for gold, present in gossan above massive sulphide, producing approximately one million tonnes grading 1.79 g/t Au. Three of the 11 mined base-metal deposits also had a gossan cap, from which gold was extracted. In 2012, the value of production from the Bathurst Mining Camp exceeded $670 million and accounted for 58 percent of total mineral production in New Brunswick.Base-metal production started in the BMC in 1957 from deposits at Heath Steele Mines, followed by Wedge in 1962, Brunswick No. 12 in 1964, Brunswick No. 6 in 1965, Caribou in 1970, Murray Brook, Stratmat Boundary and Stratmat N-5 in 1989, Captain North Extension in 1990, and lastly, Half Mile Lake in 2012. The only mine in continuous production for most of this time was Brunswick No. 12. During its 49-year lifetime (1964–2013), it produced 136,643,367 tonnes of ore grading 3.44$46 billion. Adding to this figure is production from the other mines in the BMC, along with money injected into the local economy from annual exploration expenditures (100s of $1000s per year) over 60 years. Several environmental measures were initiated in the BMC, including the requirement to be clean shaven and carry a portable respirator (now applied to all mines in Canada); ways to treat acid mine drainage and the thiosalt problem that comes from the milling process; and pioneering studies to develop and install streamside-incubation boxes for Atlantic Salmon eggs in the Nepisiguit River, which boosted survival rates to over 90$ par an) sur 60 ans. Plusieurs mesures environnementales ont été lancées dans le CMB, y compris l'exigence d'être rasé de près et de porter un respirateur portatif (maintenant appliqué à toutes les mines au Canada); les moyens de traitement des effluents miniers acides et le problème des thiosels qui proviennent du processus de broyage; et les études pionnières pour développer et installer des boîtes d'incubation en bord de rivière pour les œufs de saumon de l'Atlantique dans la rivière Nepisiguit, ce qui a fait passer les taux de survie à plus de 90%. En ce qui concerne les infrastructures, les routes provinciales 180 et 430 n'existeraient pas sans la découverte du CMB; la fonderie de plomb et le port en eau profonde de Belledune non plus. Les innovations minières sont trop nombreuses pour être énumérées dans ce résumé, le lecteur est donc renvoyé au texte principal. En ce qui concerne les effets sociaux, les nouvelles possibilités, la nouvelle richesse et la formation offertes par l'industrie minière ont radicalement changé le niveau de vie et le tissu social du nord du Nouveau-Brunswick. Ce qui avait été une société rurale en grande partie pauvre, principalement tributaire des industries de la pêche et de la sylviculture, est devenu une communauté moderne florissante. De plus, un nombre incalculable d’ingénieurs, de géologues, de mineurs et de prospecteurs «se sont fait les dents» au CMB, et bon nombre d’entre eux ont continué à faire leurs marques dans d’autres régions du Canada et du monde

Emerging viral diseases of fish and shrimp

The rise of aquaculture has been one of the most profound changes in global food production of the past 100 years. Driven by population growth, rising demand for seafood and a levelling of production from capture fisheries, the practice of farming aquatic animals has expanded rapidly to become a major global industry. Aquaculture is now integral to the economies of many countries. It has provided employment and been a major driver of socio-economic development in poor rural and coastal communities, particularly in Asia, and has relieved pressure on the sustainability of the natural harvest from our rivers, lakes and oceans. However, the rapid growth of aquaculture has also been the source of anthropogenic change on a massive scale. Aquatic animals have been displaced from their natural environment, cultured in high density, exposed to environmental stress, provided artificial or unnatural feeds, and a prolific global trade has developed in both live aquatic animals and their products. At the same time, over-exploitation of fisheries and anthropogenic stress on aquatic ecosystems has placed pressure on wild fish populations. Not surprisingly, the consequence has been the emergence and spread of an increasing array of new diseases. This review examines the rise and characteristics of aquaculture, the major viral pathogens of fish and shrimp and their impacts, and the particular characteristics of disease emergence in an aquatic, rather than terrestrial, context. It also considers the potential for future disease emergence in aquatic animals as aquaculture continues to expand and faces the challenges presented by climate change

Patterns of past and recent conversion of indigenous grasslands in the South Island, New Zealand

We used recent satellite imagery to quantify the extent, type, and rate of conversion of remaining indigenous grasslands in the inland eastern South Island of New Zealand in recent years. We describe the pattern of conversion in relation to national classifications of land use capability and land environments, and ecological and administrative districts and regions. We show that although large areas of indigenous grasslands remain, grassland loss has been ongoing. Indigenous grassland was reduced in the study area by 3% (70 200 ha) between 1990 and 2008. Almost two-thirds of post-1990 conversion occurred in threatened environments with less than 30% of indigenous cover remaining, primarily in the Waitaki, Mackenzie and Central Otago administrative districts. This conversion occurred primarily on non-arable land. In the Mackenzie and Waitaki districts the rate of conversion in 2001-2008 was approximately twice that in 1990-2001. Opportunities to protect more of the full range of indigenous grasslands lie with the continuing tenure review process in these districts