How powerful is demography ? The Serendipity Theorem revisited

Introduced by Samuelson (1975), the Serendipity Theorem states that the competitive economy will converge towards the optimum steady-state provided the optimum population growth rate is imposed. This paper aims at exploring whether the Serendipity Theorem still holds in an economy with risky lifetime. We show that, under general conditions, including a perfect annuity market with actuarially fair return, imposing the optimum fertility rate and the optimum survival rate leads the competitive economy to the optimum steady-state. That Extended Serendipity Theorem is also shown to hold in economies where old adults work some fraction of the old-age, whatever the retirement age is fixed or chosen by the agentsSerendipity Theorem, fertility, mortality, overlapping generations, retirement

Dynamics and monetary policy in a fair wage model of the business cycle

We first build a fair wage model in which effort varies over the business cycle. This mechanism decreases the need for other sources of sluggishness to explain the observed high inflation persistence. Second, we confront empirically our fair wage model with a New Keynesian model based on the standard assumption of monopolistic competition in the labor market. We show that, in terms of overall fit, the fair wage model outperforms the New Keynesian one. The extension of the fair wage model with lagged wage is judged insignificant by the data, but the extension based on a rent sharing argument including firm’s productivity gains in the fair wage is not. Looking at the implications for monetary policy, we conclude that the additional trade-off problem created by the inefficient real wage behavior significantly affects nominal interest rates and inflation outcomesEfficiency wage, effort, inflation persistence, monetary policy

Dynamics and monetary policy in a fair wage model of the business cycle

We first build a fair wage model in which effort varies over the business cycle. This mechanism decreases the need for other sources of sluggishness to explain the observed high inflation persistence. Second, we confront empirically our fair wage model with a New Keynesian model based on the standard assumption of monopolistic competition in the labor market. We show that, in terms of overall fit, the fair wage model outperforms the New Keynesian one. The extension of the fair wage model with lagged wage is judged insignificant by the data, but the extension based on a rent sharing argument including firm’s productivity gains in the fair wage is not. Looking at the implications for monetary policy, we conclude that the additional trade-off problem created by the inefficient real wage behavior significantly affect nominal interest rates and inflation outcomes. JEL Classification: E4, E5efficiency wage, effort, Inflation persistence, monetary policy

Dynamics and monetary policy in a fair wage model of the business cycle

We first build a fair wage model in which effort varies over the business cycle. This mechanism decreases the need for other sources of sluggishness to explain the observed high inflation persistence. Second, we confront empirically our fair wage model with a New Keynesian model based on the standard assumption of monopolistic competition in the labor market. We show that, in terms of overall fit, the fair wage model outperforms the New Keynesian one. The extension of the fair wage model with lagged wage is judged insignificant by the data, but the extension based on a rent sharing argument including firm’s productivity gains in the fair wage is not. Looking at the implications for monetary policy, we conclude that the additional trade-off problem created by the inefficient real wage behavior significantly affect nominal interest rates and inflation outcomesEfficiency wage, effort, inflation persistence, monetary policy

Automated Approaches to Bowhead Whale Identification

This project aims to automate the identification of bowhead whales using convolutional neural networks. The initial neural network identifies key points to outline each whale and uses these points to divide each whale into three sub-sections: the fluke, the back, and the head. Upon segmenting the whale, each sub-section was used to identify individual bowhead whales through the white patterns and scarring on their backs. The results from each segment were then combined into a final classifier to identify bowhead whales

In Praise of Investor Irrationality

How should a market filled with investors who chronically make bad investments, but is nevertheless efficient, be regulated? A growing body of evidence suggests that this is the state of most securities markets; investors rely on cognitive processes that produce systematically bad choices, and yet the market remains largely efficient. In fact, cognitive errors might be essential to their efficient operation. Even investors who make systematic errors also often possess real and unique information that can contribute to accurate pricing of securities. If such investors became mindful of their limited ability to distinguish between real information and erroneous information, they would decline to rely on their beliefs to invest and would thereby withhold private information from the market. Over-confidence on the part of these investors leads them to trade anyway. This over-confidence provides market liquidity, but more importantly, provides the market with the private information that individual investors possess (but should, rationally, withhold). Hence, reforms designed to save investors from the costs of their cognitive errors would reduce market liquidity and deprive the market of valuable information. In short, markets need irrationality

In Praise of Investor Irrationality

How should a market filled with investors who chronically make bad investments, but is nevertheless efficient, be regulated? A growing body of evidence suggests that this is the state of most securities markets; investors rely on cognitive processes that produce systematically bad choices, and yet the market remains largely efficient. In fact, cognitive errors might be essential to their efficient operation. Even investors who make systematic errors also often possess real and unique information that can contribute to accurate pricing of securities. If such investors became mindful of their limited ability to distinguish between real information and erroneous information, they would decline to rely on their beliefs to invest and would thereby withhold private information from the market. Over-confidence on the part of these investors leads them to trade anyway. This over-confidence provides market liquidity, but more importantly, provides the market with the private information that individual investors possess (but should, rationally, withhold). Hence, reforms designed to save investors from the costs of their cognitive errors would reduce market liquidity and deprive the market of valuable information. In short, markets need irrationality

Bedforms Produced on a Particle Bed by Vertical Oscillations of a Plate

We describe a new mechanism that produces bedforms and characterize the conditions under which it operates. The mechanism is associated with pressure gradients generated in a fluid saturated particle bed by a plate oscillating in the water above it. These vertical pressure gradients cause oscillatory bed failure. This facilitates particle displacement in its interior and transport at and near its surface that contribute to the formation of a heap under the plate. Flows over erodible beds generally cause shear stresses on the bed and these induce bed failure. Failure driven by pressure gradients is different from this. We report on bedforms in a bed of glass beads associated with such fluctuating pressure gradients. We measure the development of the profiles of heaps as a function of time and determine the tangential and normal motion of areas on the beds surface and estimate the depth of penetration of the tangential transport. The measurements compare favorably with a simple model that describes the onset of failure due to oscillations in pressure

Murine Hyperglycemic Vasculopathy and Cardiomyopathy: Whole-Genome Gene Expression Analysis Predicts Cellular Targets and Regulatory Networks Influenced by Mannose Binding Lectin

Hyperglycemia, in the absence of type 1 or 2 diabetes, is an independent risk factor for cardiovascular disease. We have previously demonstrated a central role for mannose binding lectin (MBL)-mediated cardiac dysfunction in acute hyperglycemic mice. In this study, we applied whole-genome microarray data analysis to investigate MBL’s role in systematic gene expression changes. The data predict possible intracellular events taking place in multiple cellular compartments such as enhanced insulin signaling pathway sensitivity, promoted mitochondrial respiratory function, improved cellular energy expenditure and protein quality control, improved cytoskeleton structure, and facilitated intracellular trafficking, all of which may contribute to the organismal health of MBL null mice against acute hyperglycemia. Our data show a tight association between gene expression profile and tissue function which might be a very useful tool in predicting cellular targets and regulatory networks connected with in vivo observations, providing clues for further mechanistic studies