Earnings Variability and Earnings Instability of Women and Men in Canada: How Do the 1990's Compare to the 1980's (Working Paper 25)

It seems to be generally assumed that earnings instability has increased in the last decade or so, as earnings inequality has widened, but is this indeed the case, and if so, to what degree? This paper builds on earlier U.S. work to look at the total variance in individuals’ earnings with a focus on the distinction between permanent earnings variation associated with factors such as human capital investments or other persistent worker attributes, and transitory earnings variation or instability for a given individual from one year to another. We find that there was an increase in overall earnings variability, especially for men, but that the greatest part of this increase was driven by the permanent component – that is, by a widening dispersion of (life-cycle) earnings differentials across workers. The increased volatility of workers’ earnings about their life-cycle earnings profiles played a secondary role in the overall increase in men’s earnings variability, whereas for women this effect was very small or even worked in the opposite direction (depending on the particular age group). Patterns by age and region are also investigated.

La teoría de los diferenciales de Salomon Maimon, la pregunta quid juris y la posibilidad de la metafísica como ciencia

Este trabajo estudia la teoría de los diferenciales de Salomon Maimon como respuesta a la cuestión quid juris y a la vez como clave para la fundamentación de la posibilidad de la metafísica como ciencia. Se reconstruye primero la crítica de Maimon al tratamiento kantiano de la pregunta quid juris. Luego, se analiza la respuesta del propio Maimon a esa pregunta, para establecer finalmente cómo tal respuesta abre el camino para la explicación de la posibilidad de la metafísica como ciencia.

Shooting for the Moon or Flying Too Near the Sun? Crossing the Value Rubicon in Precision Cancer Care

In his last two State of the Union addresses, President Barack Obama has focused on the need to deliver innovative solutions to improve human health, through the Precision Medicine Initiative in 2015 and the recently announced Cancer Moonshot in 2016. Precision cancer care has delivered clear patient benefit, but even for high-impact medicines such as imatinib mesylate (Glivec) in chronic myeloid leukaemia, the excitement at the success of this practice-changing clinical intervention has been somewhat tempered by the escalating price of this 'poster child' for precision cancer medicine (PCM). Recent studies on the costs of cancer drugs have revealed significant price differentials, which are a major causative factor behind disparities in the access to new generations of immunological and molecularly targeted agents. In this perspective, we will discuss the benefits of PCM to modern cancer control, but also emphasise how increasing costs are rendering the current approaches to integrating the paradigm of PCM unsustainable. Despite the ever increasing pressure on cancer and health care budgets, innovation will and must continue. Value-based frameworks offer one of the most rational approaches for policymakers committed to improving cancer outcomes through a public health approach.

Free Resolutions from Involutive Bases

We show that the theory of involutive bases can be combined with discrete algebraic Morse Theory. For a graded k[x0 ...,xn]-module M, this yields a free resolution G, which in general is not minimal. We see that G is isomorphic to the resolution induced by an involutive basis. It is possible to identify involutive bases inside the resolution G. The shape of G is given by a concrete description. Regarding the differential dG, several rules are established for its computation, which are based on the fact that in the computation of dG certain patterns appear at several positions. In particular, it is possible to compute the constants independent of the remainder of the differential. This allows us, starting from G, to determine the Betti numbers of M without computing a minimal free resolution: Thus we obtain a new algorithm to compute Betti numbers. This algorithm has been implemented in CoCoALib by Mario Albert. This way, in comparison to some other computer algebra system, Betti numbers can be computed faster in most of the examples we have considered. For Veronese subrings S(d), we have found a Pommaret basis, which yields new proofs for some known properties of these rings. Via the theoretical statements found for G, we can identify some generators of modules in G where no constants appear. As a direct consequence, some non-vanishing Betti numbers of S(d) can be given. Finally, we give a proof of the Hyperplane Restriction Theorem with the help of Pommaret bases. This part is largely independent of the other parts of this work.

A Comparison of the Performance of Brand-Affiliated and Unaffiliated Hotel Properties

Research has shown that performance differences exist between brand-affiliated hotels and unaffiliated properties. However, the extant empirical results are mixed. Some research has shown that brands outperform unaffiliated hotels on various metrics, whereas other research has shown the opposite. This article analyzes this issue using a matched-pair approach where we compare the performance differences of brand-affiliated and unaffiliated properties between 1998 and 2010. The matched-pair approach ensures that local competitive conditions as well as hotel characteristics are the same across the comparison pair. In addition, all potential omitted-variable bias and model misspecifications are avoided. Thus, to address our research question, we compare branded hotels with unaffiliated properties that are identical in age, market segment, location, and duration of operation, as well as having a similar number of rooms. Our analysis shows that performance differentials are present, albeit not systematic. We found no consistent advantages in all segments for either the affiliated hotels or the comparable unaffiliated properties, taking into account our comparison factors. That said, the methodology of our approach yields results that are more informative to the affiliation choice of owners and to the growth strategies of hotel brand–owner companies than those of previous empirical studies.

Values and Beliefs Held About Parenting and Education by School Staff and Parents of Pupils with Special Educational Needs in the Context of Home- School Collaboration

Effective collaboration between school staff and parents of children identified as having special educational needs is considered to be an essential component of the child’s successful education. Differences in beliefs and perspectives adopted by the school staff and parents play an important role in the process of collaboration. However, little is known about the precise relationship between the beliefs and the process of collaboration. The purpose of this study was to explore the values and beliefs held by the school staff and parents in the areas of parenting and education. The study also explored the link between these beliefs and the process of collaboration within four parent-teacher dyads from mainstream primary schools. Focus groups and semi-structured interviews based on repertory grid technique were used. The findings highlighted an overall similarity in the participants’ views on collaboration and in their important beliefs about parenting and education. At the same time, differences in perspectives adopted by parents and teachers were also identified. The author discusses how these differences in perspectives are manifested in the process of collaboration from the point of Cultural Capital Theory. The factors such as power differentials, trust between parents and teachers, and limited resources and constraints of educational system are highlighted. Implication for practice for teachers and educational psychologists are discussed.

Forecasting exchange rates in the presence of instabilities

Many exchange rate papers articulate the view that instabilities constitute a major impediment to exchange rate predictability. In this thesis we implement Bayesian and other techniques to account for such instabilities, and examine some of the main obstacles to exchange rate models' predictive ability. We first consider in Chapter 2 a time-varying parameter model in which fluctuations in exchange rates are related to short-term nominal interest rates ensuing from monetary policy rules, such as Taylor rules. Unlike the existing exchange rate studies, the parameters of our Taylor rules are allowed to change over time, in light of the widespread evidence of shifts in fundamentals - for example in the aftermath of the Global Financial Crisis. Focusing on quarterly data frequency from the crisis, we detect forecast improvements upon a random walk (RW) benchmark for at least half, and for as many as seven out of 10, of the currencies considered. Results are stronger when we allow the time-varying parameters of the Taylor rules to differ between countries. In Chapter 3 we look closely at the role of time-variation in parameters and other sources of uncertainty in hindering exchange rate models' predictive power. We apply a Bayesian setup that incorporates the notion that the relevant set of exchange rate determinants and their corresponding coefficients, change over time. Using statistical and economic measures of performance, we first find that predictive models which allow for sudden, rather than smooth, changes in the coefficients yield significant forecast improvements and economic gains at horizons beyond 1-month. At shorter horizons, however, our methods fail to forecast better than the RW. And we identify uncertainty in coefficients' estimation and uncertainty about the precise degree of coefficients variability to incorporate in the models, as the main factors obstructing predictive ability. Chapter 4 focus on the problem of the time-varying predictive ability of economic fundamentals for exchange rates. It uses bootstrap-based methods to uncover the time-specific conditioning information for predicting fluctuations in exchange rates. Employing several metrics for statistical and economic evaluation of forecasting performance, we find that our approach based on pre-selecting and validating fundamentals across bootstrap replications generates more accurate forecasts than the RW. The approach, known as bumping, robustly reveals parsimonious models with out-of-sample predictive power at 1-month horizon; and outperforms alternative methods, including Bayesian, bagging, and standard forecast combinations. Chapter 5 exploits the predictive content of daily commodity prices for monthly commodity-currency exchange rates. It builds on the idea that the effect of daily commodity price fluctuations on commodity currencies is short-lived, and therefore harder to pin down at low frequencies. Using MIxed DAta Sampling (MIDAS) models, and Bayesian estimation methods to account for time-variation in predictive ability, the chapter demonstrates the usefulness of suitably exploiting such short-lived effects in improving exchange rate forecasts. It further shows that the usual low-frequency predictors, such as money supplies and interest rates differentials, typically receive little support from the data at monthly frequency, whereas MIDAS models featuring daily commodity prices are highly likely. The chapter also introduces the random walk Metropolis-Hastings technique as a new tool to estimate MIDAS regressions.

L’effet à long terme de la vie reproductive sur la mortalité des femmes en milieu rural sénégalais

Population ageing in sub-Saharan Africa raises new concerns about mature adult mortality patterns and differentials, but little is known in this region due to the lack of data. This study examines the long term effects of reproductive history on female mortality in three local rural areas in Senegal where population have been followed up for decades. We study mortality differentials according to the past reproductive history of females aged between 50 and 70 in the period 1985-2011. We find that age at first and last deliveries impact mortality levels, as does the number of children ever born. Looking at the sex of the childrenand their vital status at age 5, we note that the number of boys is negatively associated with mortality rates, by a larger extent than the number of girls. In virilocal societies, social factors probably have a strong impact. This result opens future research avenues on the issue of the care of the elderly.

The young, educated, minorities and the poor move out from south central Ethiopia

High population growth fragmented rural landholdings leading to low harvests and crop yields per acre per annum creating surplus labour that may resort to migration as a coping mechanism in least developing countries including Ethiopia. The main aim of the study is to assess trends and differentials of out-migration in south central Ethiopia. The Butajira demographic surveillance system database from 1987 to 2008 was used to conduct event history analysis. There were 3.97 out-migrations per 100 person years. Probability of out-migration was higher among males, teenagers, the youth, completed primary and secondary plus education; not in marital union; Christians, urbanites; lived in rented and owed house compared to their respective counterparts. The higher chances of out-migration among these groups may have social and economic significance.

Three essays on corporate taxation : financial reporting, value, and firm creation

Doutoramento em Gestão

Predictors of Adolescent Sexual Intentions and Behavior: Attitudes, Parenting, and Neighborhood Risk

The current study was a cross-sectional examination of data collected during an HIV risk reduction intervention in south Florida. The purpose of the study was to explore the relationships between neighborhood stress, parenting, attitudes, and adolescent sexual intentions and behavior. The Theory of Planned Behavior was used as a model to guide variable selection and propose an interaction pathway between predictors and outcomes. Potential predictor variables measured for adolescents ages 13-18 (n=196) included communication about sex, parent-family connectedness, parental presence, parent-adolescent activity participation, attitudes about sex and condom use, neighborhood disorder, and exposure to violence. Outcomes were behavioral intentions and sexual behavior for the previous eight months. Neighborhood data was supplemented with ZIP Code level data from regional sources and included median household income, percentage of minority and Hispanic residents, and number of foreclosures. Statistical tests included t-tests, Pearson’s correlations, and hierarchical linear regressions. Results showed that males and older adolescents reported less positive behavioral intentions than females and adolescents younger than 16. Intentions were associated with condom attitudes, sexual attitudes, and parental presence; unprotected sexual behavior was associated with parental presence. The best fit model for intentions included gender, sexual attitudes, condom attitudes, parental presence, and neighborhood disorder. The unsafe sexual behavior model included whether the participant lived with both natural parents in the previous year, and the percent of Hispanic residents in the neighborhood. Study findings indicate that more research on adolescent sexual behavior is warranted, specifically examining the differentials between variables that affect intentions and those that affect behavior. A focus on gender and age differences during intervention development may allow for better targeting and more efficacious interventions. Adding peer and media influences to the framework of attitudes, parenting, and neighborhood may offer more insight into patterns of adolescent sexual behavior risk.

América Latina y el Caribe: Variables de competitividad para la dinámica empresarial 2007 - 2014

Este estudio realiza una categorización regional de los países en América Latina con respecto de las categorizaciones globales teniendo en cuenta los índices de competitividad, crecimiento económico y desarrollo humano. El objetivo es actualizar los análisis sobre la situación regional de forma cuantitativa involucrando el grado de asimetría en la competitividad. Esta relación entre el posicionamiento global y regional ha influenciado directamente la evolución del tejido empresarial

Diferencias regionales en las estructuras de ingresos laborales en Colombia

Dada la persistencia de las diferencias en ingresos laborales por regiones en Colombia, el presente artículo propone cuantificar la magnitud de este diferencial que es atribuida a la diferencia en estructuras de mercado laboral, entendiendo esta última como la diferencia en los retornos a las características de la fuerza laboral. Para ello se propone el uso de un método de descomposición del tipo Oaxaca- Blinder y se compara a Bogotá –la ciudad con mayores ingresos laborales- con otras ciudades principales. Los resultados obtenidos al conducir el ejercicio de descomposición muestran que las diferencias en estructura están a favor de Bogotá y que estas explican más de la mitad de la diferencia total, indicando que si se quieren reducir las disparidades de ingresos laborales entre ciudades no es suficiente con calificar la fuerza laboral y que es necesario indagar por las causas que hacen que los retornos a las características difieran entre ciudades.