Increasing optimism and demand uncertainty

By allowing the initial prior over market size to be a mixture of distributions, this paper extends the model of irreversible investment under uncertainty proposed by Rob (1991). We find that capacity expansion fuels investors' optimism. It is shown in the paper that the crash is always preceded by a boom when the initial prior is a mixture of exponential distributions.Learning Investment Uncertainty

The Wrong Kind of Transparency

In a model of career concerns for experts, when is the principal hurt from observing more information about her agent? This paper introduces a distinction between information on the consequence of the agent's action and information directly on the agent's action. It is the latter kind that can hurt the principal by engendering conformism, which worsens both discipline and sorting. The paper identifies a necessary and sufficient condition on the agent signal structure under which transparency on action is detrimental to the principal. The paper also shows the existence of complementarities between transparency on action and transparency on consequence. The results are used to interpret existing disclosure policies in politics, corporate governance, and delegated portfolio management.Transparency, career concerns, expert agents.

Numerical investigation into the failure of a micropile retaining wall

The paper presents a numerical investigation on the failure of a micropile wall that collapsed while excavating the adjacent ground. The main objectives are: to estimate the strength parameters of the ground; to perform a sensitivity analysis on the back slope height and to obtain the shape and position of the failure surface. Because of uncertainty of the original strength parameters, a simplified backanalysis using a range of cohesion/friction pairs has been used to estimate the most realistic strength parameters. The analysis shows that failure occurred because overestimation of strength and underestimation of loads.Peer ReviewedPostprint (author's final draft

Campaign Advertising and Voter Welfare

This paper investigates the role of campaign advertising and the opportunity of legal restrictions on it. An electoral race is modeled as a signalling game with three classes of players: a continuum of voters, two candidates, and one interest group. The group has non-verifiable insider information on the candidates' valence and, on the basis of this information, offers a contribution to each candidate in exchange for a favorable policy position. Candidates spend the contributions they receive on non-directly informative advertising. This paper shows that: (1) A separating equilibrium exists in which the group contributes to a candidate only if the insider information about that candidate is positive; (2) Although voters are fully rational, a ban on campaign advertising can be welfare-improving; and (3) Split contributions may arise in equilibrium (and should be prohibited).Elections;campaign contributions;advertising;voter welfare;split contributions

Non-existence of reflectionless measures for the s-Riesz transform when 0<s<1

A measure $\mu$ on $\mathbb{R}^d$ is called reflectionless for the $s$-Riesz transform if the singular integral $R^s\mu(x)=\int \frac{y-x}{|y-x|^{s+1}}\,d\mu(y)$ is constant on the support of $\mu$ in some weak sense and, moreover, the operator defined by $R^s_\mu(f)=R^s(f\,\mu)$ is bounded in $L^2(\mu)$. In this paper we show that the only reflectionless measure for the $s$-Riesz transform is the zero measure when $0<s<1$.Comment: 11 page

Nonuniversal conductivity exponents in continuum percolating Gaussian fractures

We study the electrical and hydraulic conductivity percolation exponents in a Gaussian fracture using the method proposed in Plouraboué et al. [Phys. Rev. E 73, 036305, 2006]. Nonuniversal conductivity percolation exponents are found: they differ from the theoretical predictions for infinite system size for frozen power-law distributions of local conductivities, as with their finite size corrections. In the hydraulic case, we also find that the probability density function of the conductivity follows a power-law distribution near the percolation threshold

Common Agency and Computational Complexity: Theory and Experimental Evidence

In a common agency game, several principals try to influence the behavior of an agent. Common agency games typically have multiple equilibria. One class of equilibria, called truthful, has been identified by Bernheim and Whinston and has found widespread use in the political economy literature. In this paper we identify another class of equilibria, which we call natural. In a natural equilibrium, each principal offers a strictly positive contribution on at most one alternative. We show that a natural equilibrium always exists and that its computational complexity is much smaller than that of a truthful equilibrium. To compare the predictive power of the two concepts, we run an experiment on a common agency game for which the two equilibria predict a different equilibrium alternative. The results strongly reject the truthful equilibrium. The alternative predicted by the natural equilibrium is chosen in 65% of the matches, while the one predicted by the truthful equilibrium is chosen in less than 5% of the matches.lobbying;experimental economics;common agency;truthful equilibrium;natural equilibrium;computational complexity

A one dimensional model for the prediction of extraction yields in a two phases modified twin-screw extruder

Solid/liquid extraction is performed on raw plant substrate with a modified twin-screw extruder (TSE) used as a thermo-mecanochemical reactor. Visual observations and experimental residence time distributions (RTD) are used to develop a solid transport model based on classical chemical engineering method. Modeled and experimental residence times are compared. The transport model is then coupled with a reactive extraction model in order to predict extraction yields