On social security financial crisis

We indicate that financial crisis in social security programs might be endogenous because social security affects fertility and human capital's decisions and thus, the aggregate growth rate of the economy. These effects lead to an endogenous erosion of the financial basis of the PAYG social security program so that, as a consequence, the PAYG system is not sustainable and it requires continuous increases in the social security tax rate. I received helpful comments in an earlier version of this paper from G.S. Becker, Larry Sjaastad, two anonymous referees and participants at seminars at Pontificia Universidad Catolica de Chile and The University of Chicago. Remaining errors are my own responsibility. Responsible editor: Junsen Zhang.     

GLUTTONY AND SLOTH? CALORIES,LABOR MARKET ACTIVITY AND THE RISE OF OBESITY

The rise in obesity has largely been attributed to an increase in calorie consumption. We show that official government household survey data indicate that levels of calorie consumption have declined in England between 1980 and 2013; while there has been an increase in calories from food eaten out at restaurants, fast food, soft drinks and confectionery, overall there has been a decrease in total calories purchased. Households have shifted towards more expensive calories, both by substituting away from home production towards market production, and substituting towards higher quality foods. We show that the decline in calories can be partially, but not entirely, rationalized with weight gain by a decline in the strenuousness of work and daily life. (JEL: D12, I12, I18)     

Vector quantization of amino acids: Analysis of the HIV V3 loop region

This paper is about techniques for clustering sequences such as nucleic or amino acids. Our application is to defining viral subtypes of HIV on the basis of similarities of V3 loop region amino acids of the envelope (env) gene. The techniques introduced here could apply with virtually no change to other HIV genes as well as to other problems and data not necessarily of viral origin. These algorithms as they apply to quantitative data have found much application in engineering contexts to compressing images and speech. They are called vector quantization and involve a mapping from a large number of possible inputs into a much smaller number of outputs. Many implementations, in particular those that go by the name generalized Lloyd or k-means, exist for choosing sets of possible outputs and mappings. With each there is an attempt to maximize similarities among inputs that map to any single output, or, alternatively, to minimize some measure of distortion between input and output. Here, two standard types of vector quantization are brought to bear upon the cited problem of clustering V3 loop amino acid sequences. Results of this clustering are compared to those of the well known UPGMA algorithms, the unweighted pair group method in which arithmetic averages are employed.     

A GAME THEORETIC ANALYSIS OF VOLUNTARY EUTHANASIA AND PHYSICIAN ASSISTED SUICIDE

In countries/states where voluntary euthanasia (VE) or physician-assisted suicide (PAS) is legal, the patient's decision about whether to request VE or PAS heavily relies on the information others provide. We use the tools of microeconomic theory to study how communication between the patient, his family and his physician influences the patient's decision. We argue that families have considerable power over the patient and that the amount of information that is transmitted from physician to patient might be severely diminished as a result of legalizing VE or PAS. We discuss our main results in the context of the ongoing normative debate over the legalization of VE and PAS. (JEL D8, I12)     

Macroeconomic Uncertainty Through the Lens of Professional Forecasters

ABSTRACT

We analyze the evolution of macroeconomic uncertainty in the United States, based on the forecast errors of consensus survey forecasts of various economic indicators. Comprehensive information contained in the survey forecasts enables us to capture a real-time measure of uncertainty surrounding subjective forecasts in a simple framework. We jointly model and estimate macroeconomic (common) and indicator-specific uncertainties of four indicators, using a factor stochastic volatility model. Our macroeconomic uncertainty estimates have three major spikes has three major spikes aligned with the 1973–1975, 1980, and 2007–2009 recessions, while other recessions were characterized by increases in indicator-specific uncertainties. We also show that the selection of data vintages affects the estimates and relative size of jumps in estimated uncertainty series. Finally, our macroeconomic uncertainty has a persistent negative impact on real economic activity, rather than producing “wait-and-see” dynamics.     

Copper mining productivity: Lessons from Chile

Chile represents almost one third of the world’s copper production. Mining is one of the main industries that contributes to our country’s development with resources and is globally recognized. Due to the end of the commodity cycle, improving productivity will be a key variable in mining performance in incoming years. This paper studies mining productivity in Chile by relying on two indicators: measure of the total factor productivity (TFP) using the traditional Solow methodology, and labor productivity. Since 2000, we found a decrease in TFP, explained mainly by the participation of capital as well as diverse factor adjustments to labor and capital inputs. Average labor productivity also decreases 42% from 1999 to 2010, a decrease explained by four determinants: real mining wages, electricity prices, copper prices and mineral grade. Since 2010, average labor productivity has increased 30%, and there is also an opportunity for additional improvement by reducing energy costs as well as by aligning productivity and labor performances.     

Structured Coupling of Probability Loss Distributions: Assessing Joint Flood Risk in Multiple River Basins

Losses due to natural hazard events can be extraordinarily high and difficult to cope with. Therefore, there is considerable interest to estimate the potential impact of current and future extreme events at all scales in as much detail as possible. As hazards typically spread over wider areas, risk assessment must take into account interrelations between regions. Neglecting such interdependencies can lead to a severe underestimation of potential losses, especially for extreme events. This underestimation of extreme risk can lead to the failure of riskmanagement strategies when they are most needed, namely, in times of unprecedented events. In this article, we suggest a methodology to incorporate such interdependencies in risk via the use of copulas. We demonstrate that by coupling losses, dependencies can be incorporated in risk analysis, avoiding the underestimation of risk. Based on maximum discharge data of river basins and stream networks, we present and discuss different ways to couple loss distributions of basins while explicitly incorporating tail dependencies. We distinguish between coupling methods that require river structure data for the analysis and those that do not. For the later approach we propose a minimax algorithm to choose coupled basin pairs so that the underestimation of risk is avoided and the use of river structure data is not needed. The proposed methodology is especially useful for large‐scale analysis and we motivate and apply our method using the case of Romania. The approach can be easily extended to other countries and natural hazards.     

Employing the Components of the Human Development Index to Drive Resources to Educational Policies

A new form of composition of the indicators employed to generate the United Nations Human Development Index (HDI) is presented here. This form of composition is based on the assumption that random errors affect the measurement of each indicator. This assumption allows for replacing the vector of evaluations according to each indicator by vectors of probabilities of being the best or the worst according to such attribute. The probabilistic composition of such probabilities of preference according to each indicator into probabilities of being the best or the worst according to all of them generates indices that may unveil, on one hand, performances to be followed and, on the other hand, extreme conditions that an additive composition would hide. Differences between the results of application of the diverse forms of composition are examined in the case of the HDI and in the case of the districts version of the HDI employed to compare Brazilian municipalities. It is verified that the smallest correlation between the education enrolment rate and the other indicators in the Brazilian case enlarges such differences.     

Reduction by half: the impact on bees of 34 years of urbanization

Urban ecosystems are growing rapidly and urbanization is an important cause of the loss of biodiversity. Bees are declining in abundance worldwide, including urban areas, and this decline is alarming because of their global importance as plant pollinators. Here we examine that decline by comparing a bee assemblage sampled in the 1980s and again in 2015, in an urban area of the city of Curitiba. Both studies sampled assemblages with hand-nets every two weeks during one year of study. Bee species richness has declined by 45% (112 species then, 63 today). Two species that have disappeared, Gaesischia fulgurans (Holmberg, 1903) and Thectochlora basiatra (Strand, 1910), have also disappeared elsewhere in the city. Also, relative abundances of species have changed, notably with the increase of social bees. Large bees that nest in cavities have also increased relative to small bees that nest in the ground. These findings are similar with previous reports indicating the sensibility of bees to urbanization. The increase in paved areas, in urban population and in exotic plants are all probably responsible for the sharp decline in bee diversity and abundance.