Showing papers by "Government of Canada published in 1996"

Photodegradation of methylmercury in lakes

Abstract: METHYLMERCURY can accumulate in fish to concentrations that threaten human health1. Fish methylmercury concentrations are high in many reservoirs2 and acidic lakes3, and also in many remote lakes4,5—a fact that may be related to increased atmospheric deposition of anthropogenically mobilized mercury during the past few decades6. Although sources of methylmercury to lakes and reservoirs are known7, in-lake destruction has not been demonstrated to occur at the low concentrations found in most water bodies. Here we report in situ incubations of lake water that show that methylmercury is decomposed by photo- degradation in surface waters. This process is abiotic and the rate is first-order with respect to methylmercury concentration and the intensity of solar radiation. In our study lake, the calculated annual rates of methylmercury photodegradation are almost double the estimated external inputs of methylmercury from rain, snow, streamflow and land runoff, implying the existence of a large source of methylmercury from bottom sediments. Photodegradation could also be an important process in the mercury cycle of other aquatic systems. This discovery fundamentally changes our understanding of aquatic mercury cycling, and challenges the long-accepted view that microbial demethylation dominates methylmercury degradation in natural fresh waters.

Provincial Credit Ratings in Canada: An Ordered Probit Analysis

Abstract: L'auteure utilise la methode des probits ordonnes pour estimer les relations entre les cotes de solvabilite octroyees aux provinces par Standard & Poor's et un certain nombre de variables economiques. Les resultats s'averent significatifs dans le cas de toutes les variables estimees. En particulier, l'auteure constate, sur la foi d'un echantillon regroupant les donnees de neuf provinces, que les declassements se produisent a peu pres au meme rythme a differents niveaux du ratio de la dette au PIB.

Overnight Rate Innovations as a Measure of Monetary Policy Shocks in Vector Autoregressions

Abstract: Les auteurs exploitent des modeles a vecteur autoregressif pour examiner la pertinence du taux du financement a un jour de la Banque du Canada comme variable de politique monetaire. Puisque la serie de taux du financement a un jour que la Banque utilise a l'heure actuelle ne commence qu'en 1971, les auteurs y greffent des taux des prets au jour le jour de maniere a obtenir une periode d'observation d'une duree suffisante.

Does Inflation Uncertainty Vary with the Level of Inflation

Abstract: L'objectif des auteurs est de tester l'hypothese que l'incertitude entourant l'inflation s'accroit lorsque le taux d'inflation augmente. Ils fondent leur analyse sur l'utilisation de modeles autoregressifs conditionnellement heteroscedastiques generalises (GARCH), lesquels permettent a la variance conditionnelle du terme d'erreur de fluctuer dans le temps. Comme cette variance constitue une approximation de l'incertitude entourant l'inflation, la detection d'une relation positive entre elle et l'inflation viendrait etayer l'hypothese examinee.

A Distant-Early-Warning Model of Inflation Based on M1 Disequilibria

Abstract: Les auteurs de la presente etude sont parvenus a la conclusion qu'un modele de correction des erreurs qui prevoit l'evolution du taux d'inflation entre le trimestre de la prevision et les huit trimestres subsequents fournit d'importants renseignements avances sur l'evolution de l'inflation

Micro-PIXE studies of Sr zoning in Arctic charr otoliths: migratory behaviour and stock discrimination

Abstract: Micro-PIXE has been used to determine the content of strontium in the growth zones of Arctic charr otoliths A well-defined correspondence is observed between the optically observed growth zones and the strontium zoning pattern Line-scan data indicate whether or not the fish concerned is anadromous, and they define the years in which migration to the sea has taken place; they also are sensitive to the geographic origin of the fish These results suggest that micro-PIXE can be a useful tool in the management and conservation of the Arctic charr

An Econometric Examination of the Trend Unemployment Rate in Canada

Abstract: This paper attempts to identify the trend unemployment rate, an empirical concept, using cointegration theory. The authors examine whether there is a cointegrating relationship between the observed unemployment rate and various structural factors, focussing neither on the non-accelerating-inflation rate of unemployment (NAIRU) nor on the natural rate of unemployment, but rather on the trend unemployment rate, which they define in terms of cointegration.

Effects of cadmium on foraging behaviour of lake charr, Salvelinus namaycush

Abstract: Foraging behaviour of lake charr, Salvelinus namaycush, exposed to 0.5 and 5.0 μg l−1 cadmium concentrations for 106–112 d, was examined in a flow-through stream channel using fathead minnows, Pimephales promelas, as prey. Five modes of foraging behaviour were observed and quantified (ending at fixate-orient; ending at approach and/or chase; ending at failed attack; ending at capture and loss; successful consumption). Each mode represented an increasingly progressive end-point from initial sighting of the prey to final consumption. Compared to controls., 0.5 μg l−1 Cd-exposed predators captured significantly fewer prey, while 5 μg l−1 Cd-exposed predators made fewer attacks. Both Cd-exposed groups consumed fewer prey than controls.

The Commodity-Price Cycle and Regional Economic Performance in Canada

Abstract: Cette etude tente de fournir une interpretation de l'evolution economique regionale depuis le debut des annees 1970. Comme il est mentionne dans le titre, nous croyons que les variations des termes de l'echange, lesquelles sont souvent reliees aux changements dans les prix des matieres premieres, expliquent une partie importante de l'evolution economique des differentes regions du Canada.

Interpreting Money-Supply and Interest-Rate Shocks as Monetary-Policy Shocks

Abstract: In this paper two shocks are analysed using Canadian data: a money-supply shock ("M-shock") and an interest-rate shock ("R-shock"). Money-supply shocks are derived using long-run restrictions based on long-run propositions of monetary theory. Thus, an M-shock is represented by an orthogonalized innovation in the trend shared by money and prices.

Longitudinal Aspects of Earnings Inequality in Canada

Abstract: In this paper we ask the three following questions: 1) Even after controlling for cyclical effects, do new spells of low earnings now last longer than they used to? 2) Once a male worker starts a new spell of low earnings, does he receive lower real annual wages now than his counterparts did in the mid-seventies? 3) Has long-term inequality in earnings risen in the eighties? The answers to these questions are the following. First, even after taking account of the relatively high unemployment rates observed since the mid-eighties, it was harder for Canadian male workers, especially those aged 18-24, to move out of the bottom of the earnings distribution during the 1985-93 period than during the 1975-84 period. In other terms, new spells of low earnings now last longer for these workers. Second, real annual wages received by young males who went through a new spell of low earnings were significantly lower in 1985-93 than in 1975-84. Third, during the eighties, inequality in earnings cumulated over either six or ten years rose at the same pace as inequality in annual earnings.

Changes in Job Tenure and Job Stability in Canada

Abstract: Using monthly data from the Canadian Labor Force Survey, the author investigates changes in the complete lengths of new job spells from 1981 through 1994. While the average complete length of new jobs did not increase or decrease over the period, changes in the distribution of complete job lengths suggest that there is an increase in the proportion of short-term jobs and a decrease in the proportion of medium-term jobs created over the period. The proportion of long-term jobs remained unchanged. This pattern of change was found among virtually all demographic subgroups examined suggesting that an economy-wide (rather than a sectoral or demographic) explanation must be sought.

Unemployment in the Stock and Flow

Abstract: A framework for the dynamic analysis of unemployment is presented and applied to Canadian and U.S. data. The focus of the analysis is upon the distinction between being unemployed and becoming unemployed, that is, between the stock and the flow of unemployment. The share of a particular group in the stock of unemployed will differ from its share in the flow into unemployment to the extent that the average duration of unemployment for the group differs from the economy-wide average. An analysis of Canadian and U.S. data leads to a series of stylized facts that permit a deeper understanding of unemployment in the two countries and of the differences between them. Significant differences in the average duration of unemployment imply that stock shares are not good indicators of flow shares; changes in the stock share of some groups are due to changes in the flow share, while for others they are due to changes in the length of unemployment spells. Explanations of the Canada-U.S. unemployment rate gap should try to accommodate at least three facts uncovered by the analysis: 1) that employer-initiated permanent separations are the primary means of entry into unemployment in Canada, while labor force entry plays a more important role in the U.S.; 2) unemployment spells are significantly longer in Canada than in the U.S. because of longer spells for most groups regardless of reason for unemployment, not because of a compositional difference in the make up of the unemployed; and 3) that longer spell duration and a higher incidence of unemployment contribute about equally to the trend increase in the Canada-U.S. unemployment differential during the 1980s.

The Intergenerational Income Mobility of Canadian Men

Abstract: In this paper we use administrative data associated with the tax system to: (1) document the extent of intergenerational income mobility among Canadian men; and (2) estimate the income disadvantage (in adulthood) of being raised in a low income household. We find that there is considerable intergenerational income mobility in Canada among middle income earners, but that the inheritance of economic status is significant at both the very top and very bottom of the income distribution. About one-third of those in the bottom quartile were raised by fathers who occupied the same position in the income distribution. In fact, the income advantage of someone who had a father in the top decile over someone who had a father in the bottom decile is in the order of 40%. We also discuss some of the policy implications of these findings, as well as some of their limitations and the directions implied for future research.