Differential mortality and social security

Abstract This paper studies the normative problem of redistribution between individuals who differ in their lifespans. We discuss aspects related to the objective function and argue that aversion to multiperiod inequality should be taken into account. Then, we study the properties of the social optimum both with full information and with asymmetric information. We highlight the role of aversion to multiperiod inequality and show that it has substantial consequences on the design of Social Security schemes. In particular, we show that for a low (resp. high) aversion to multiperiod inequality, a negative (resp. positive) implicit tax rate on continued activity is desirable.     

Hinterland transportation in Europe: Combined transport versus road transport

The dominance of road for hinterland services could be challenged by using rail-road or waterway-road transport because of costs, congestion and growing environmental constraints. A common dynamic that is very favorable to the development of combined transport is shared among the actors of the transport chain but with different starting positions considering the ports of the Northern Range.But combined transport must still demonstrate that it can compete with road transport. Road transport and combined transport are not directly comparable because they do not offer the same physical transport service. The organizational patterns of road and combined transport are investigated. The example of hinterland services to and from the port of Le Havre to the Paris region is a particularly interesting case because of the very short distance. It is shown that the competitiveness of combined transport in terms of price varies greatly according to the way road transport it competes with is organized and that the commercial policy of combined transport operators plays a key role for explaining this competitiveness. Additional services such as additional dwelling times and specific custom advantages are paramount of importance to encourage the shift from road transport to combined transport.     

How to shake the invisible hand (when Robinson meets Friday)

We propose defining the invisible hand by: (i) modelling the mechanism itself (rather than just assuming its existence); and (ii) making explicit the limit conditions of its working. For that purpose, we simply assimilate the working of the invisible hand mechanism with the existence of a social preference such that individual and social optimalities are consistent. In introducing the possibility of interaction among individuals, we then suggest that the standard "singleton case," or "atomistic individualism," is just an extreme feature of a more general requirement that we call the  network agreement . Our main result is that the invisible hand mechanism does keep on working when there is an interaction between Robinson and Friday if the former (respectively, the latter) is sensitive to the latter (respectively, the former) in such a way that they exhibit some agreement in preferences. Hence, the singleton case naturally satisfies this property because neither Robinson nor Friday can disagree with himself. Further cooperative situations are also allowed in order to extent the invisible hand mechanism to cases with interactions.     

REPRODUCTION AND TEMPORARY DISEQUILIBRIUM: A CLASSICAL APPROACH

We build a bisector reproduction model with Classical features in which the capitalists aim at maximizing accumulation. At variance with gravitation models, it is assumed that they invest their profits in their own industry. Their plans are based on actual productions and expected prices. Effective prices and effective allocations of resources are determined by a market‐clearing mechanism. A law on the formation of expectations allows us to define the dynamics of disequilibria, which let appear endogenous self‐sustained fluctuations around a long‐run path. The long‐run rate of growth and the amplitude of the fluctuations depend on the initial conditions.     

PRIMITIVE ACCUMULATION,GROWTH AND THE GENESIS OF SOCIAL CLASSES

The aim of this paper is to show that inequalities of wealth can be necessary conditions to explain the apparition and rise of a capitalistic system. We try to highlight Marx's insights on primitive accumulation. Our dynamic framework is consistent with Roemer's idea of endogenous class stratification. We extend this calculation by incorporating some features of the Pasinetti–Samuelson–Modigliani model, and provide an example of possible microfoundations.     

Reproducibility investigation of elicitation techniques in risk assessment for hydraulic turbines

Abstract

Certain elicitation techniques exert some control on expert opinions by leading them to a consensus or to a specific choice. In the absence of such guidelines, experts rely on their own knowledge to formulate opinions. This can result in large dispersions and affects the decision maker’s judgment. In this situation, we wonder what the relevant elicitation techniques are and how we can help experts to express their knowledge. From literature review, it is hard to decide if elicitation techniques are equivalent or not, which justifies the reproducibility analysis that we carry out in this paper. In this study, multiple experts have been involved in order to predict the defect size in hydraulic turbines, according to four proposed elicitation techniques. The comparison between these techniques was performed based on a suggested algorithm using the area metric concept. Our Findings show that elicitation techniques with ‘support’ tend to limit variations between experts and might be suitable only when prior knowledge on the expected elicited variable is available. Otherwise, we can end up with a distorted opinion of the elicited variable and an erroneous risk assessment.     

The debt hangover: Renegotiation with noncontractible investment

This paper analyses the incentives of the equityholders of a levered company to undertake noncontractible investments. This noncontrability is shown to seriously impede the efficiency of any renegotiation process in the debt overhang problems. Conditions for obtaining a fully efficient level of investment choice are derived.     

Negative earnings,positive earnings and stock return predictability: An empirical examination of market timing

We examine the predictive ability of earnings-price ratios or yields for the S&P 500 index. We decompose the aggregate earnings-price ratio into its positive and negative components (“winners” vs “losers”) and find that the negative component has the most predictive ability. We also find that the earnings-price measures forecast both future returns and earnings growth. Our models display substantial variation in explanatory power over time with forecast power resurfacing in the latter 1990s. We conclude that to the extent that earnings-price yields predict future S&P 500 returns, the negative earnings component is the driving factor.     

A simple model of brain circulation

This paper analyzes the allocation of two types of individuals differentiated by talent between two countries where they choose to be workers or entrepreneurs. An equilibrium with international migration exists when countries' talent endowments are sufficiently different. It is consistent with one-way or two-way migration whether individuals are entrepreneurs or workers. Although allowing migration increases domestic welfare in one country and decreases it in the other, it is always supported by majority voting in both countries.     

Weather Index Drought Insurance: An Ex Ante Evaluation for Millet Growers in Niger

In the Sudano-Sahelian region, which includes South Niger, the inter-annual variability of the rainy season is high and irrigation is limited. As a consequence, bad rainy seasons have a massive impact on crop yield and regularly result in food crises. Traditional insurance policies based on crop damage assessment are not available because of asymmetric information and high transaction costs compared to the value of production. We assess the risk mitigation capacity of an alternative form of insurance which has been implemented at a large scale in India since 2003: insurance based on a weather index. We compare the efficiency of various weather indices to increase the expected utility of a representative risk-averse farmer. We show the importance of using plot-level yield data rather than village averages, which bias results due to the presence of idiosyncratic shocks. We also illustrate the need for out-of-sample estimations in order to avoid overfitting. Even with the appropriate index and assuming substantial risk aversion, we find a limited gain of implementing insurance, which roughly corresponds to, or slightly exceeds, the cost observed in India for implementing such insurance policies. However, when we separately treat the plots with and without fertilisers separately, we see that the benefit of insurance is slightly higher in the former case. This suggests that insurance policies may slightly increase the use of risk-increasing inputs such as fertilisers and improved cultivars, and hence improve average yields, which remain very low in the region.