Radiography of the distal extremity of the manus in the donkey foal: Normal images and quantitative characterization from birth to 2 years of age: A pilot study.

This study describes a radiographic survey of the anatomical development of the distal extremity of the manus in the donkey from 0 to 2 years of age. The right distal limb of 10 donkey foals, born in the spring of 2012, underwent radiographs every month for the first 6 months of age and every 3 months during the following 18 months. Latero-medial radiographs with and without barium marker at the coronary band and dorso-palmar radiographs with both front feet in weight bearing were obtained. The distal physis of the third metacarpal bone and the proximal physis of the proximal phalanx (phalanx proximalis) were closed at the mean age of 18.6 months. The distal physis of the proximal phalanx appeared as a clear radiolucent line at 2 weeks of age and was still subtly visible in some donkeys at 24 months. The proximal physis of the middle phalanx (phalanx media) was closed at the mean age of 16.7 months. The distal physis of this phalanx was visible at birth, but closed at 4 days. The distal phalanx (phalanx distalis) was triangular at birth. At the age of 20-21 months, the palmar processes (processus palmares) were both developed. The navicular bone (os sesamoideum distalis) was developed at the mean age of 9 months. The proximal sesamoid bones (ossa sesamoidea proximalia) were seen in continuously development during the 24 months. It seems that the physes in the distal extremity of the manus in the donkey close at an older age than the physes in the horse.

Longevity, genes and efforts: an optimal taxation approach to prevention.

This paper applies the analytical tools of optimal taxation theory to the design of the optimal subsidy on preventive behaviours, in an economy where longevity varies across agents, and depends on preventive expenditures and on longevity genes. Public intervention can be here justified on three grounds: corrections for misperceptions of the survival process and for externalities related to individual preventive behaviour, and redistribution across both earnings and genetic dimensions. The optimal subsidy on preventive expenditures is shown to depend on the combined impacts of misperception, externalities and self-selection. It is generally optimal to subsidize preventive efforts to an extent depending on the degree of individual myopia, on how productivity and genes are correlated, and on the complementarity of genes and preventive efforts in the survival function.

The demographics of inequality.

"This paper presents a survey of recent literature on the effects of demographic variables on economic inequality. First, a number of conceptual and methodological questions are raised and discussed. They pertain to what is meant by inequality, what the range of demographic variables is, and how variable and endogenous are the demographic variables most widely used. The paper then turns to a review of empirical works on the distributive incidence of the following demographic variables: baby boomers entering the job market, aging population, variable fertility and mortality rates, internal and external migrations, divorce and widowhood, and finally donations and bequests. It appears that a lot of caution is needed when assessing the incidence of any demographic variable changing the size of the population because in this case standard inequality measures yield conflicting signals." The geographical focus is on developed countries.

Inheritance and wealth composition.

"This paper studies the effects of variables pertaining to alternative bequest motives on the composition of households' portfolio. It relies on a 1986 survey on the assets structure of 5,600 French households. The main conclusion is that bequest motives indeed influence the composition of households' wealth.... In general, however, for lack of data but also because households have mixed bequest motives, one cannot establish a clear relation between specific models of inheritance on the one hand and wealth pattern on the other hand."

Bequests as a heir "disciple device.".

"This paper develops a model of inter vivos gifts and bequests in a setting of moral hazard and adverse selection. Altruistic parents do not perfectly know how much effort their children make to earn their living, nor do they know their true level of ability. Inter vivos gifts take place prior to the realization of the children's earnings whereas at the moment of bequests, parents do observe them. We show that an optimal transfer policy generally uses a mix of inter vivos gifts--deemed as more efficient--and bequests--deemed as more redistributive."

Population growth and optimality: when does serendipity hold?

"This note gives the conditions under which there is an interior optimum rate of population growth in a two-generations-overlapping model. These conditions imply complementarity both in production and in consumption. They also validate Samuelson's serendipity theorem."

Optimal population without repugnant aspects.

PIP: This paper presents an approach to the problem of optimum population avoiding the standard absolute repugnant solution as well as the marginal repugnant solution. Economists confront a variety of problems involving population size that is endogenously determined and can be either indirectly or directly regulated. The problem implies that an increase in each individual income leads to a drop in the optimal level of consumption. A concept axiomatized by Blackorby et al. was utilized to surmount the problem that required a critical level of use. However, critical level was not exogenous according to the assumption, but linked to the marginal contribution of each newcomer to the total resource constraint of a society.^ieng

Pay-as-you-go social security in a changing environment.

"In this paper, we examine the optimal pay-as-you-go social security scheme which reallocates resources across generations in a changing environment, that is, with fluctuations in population growth rates and in productivity levels. We use an overlapping generations model along with a social welfare function consisting of the sum of generational utilities either unweighted or weighted by population size and a discount factor. We show how intergenerational resource sharing can be used to improve social welfare even though the extent of intergenerational redistribution is hampered by payroll tax deadweight losses...." The authors also consider the effects of an economy's openness on resource sharing. The geographical focus is on developed countries.