p63 and epithelial metaplasia: a gutsy choice.

Barrett's esophagus is an epithelial metaplasia associated with an increased risk for cancer, but its underlying mechanisms have been debated. Now Wang et al. (2011) suggest an intriguing explanation for this puzzle: a population of residual embryonic cells, lacking the transcription factor p63, migrates and repopulates a normal tissue damaged by inflammation or gastroesophageal reflux.

Individual Aspirations and Satisfaction:Quantifying the Importance of Homeownership

Residential satisfaction is often used as a barometer to assess the performance of public policy and programmes designed to raise individuals' well-being. However, the fact that responses elicited from residents might be biased by subjective, non-observable factors casts doubt on whether these responses can be taken as trustable indicators of the individuals' housing situation. Emotional factors such as aspirations or expectations might affect individuals' cognitions of their true residential situation. To disentangle this puzzle, we investigated whether identical residential attributes can be perceived differently depending on tenure status. Our results indicate that tenure status is crucial not only in determining the level of housing satisfaction, but also regarding how dwellers perceive their housing characteristics. Keywords: Housing satisfaction, subjective well-being, homeownership. JEL classification: D1, R2.

Exchange rate forecasters’ performance: evidence of skill?

This paper sheds new light on a long-standing puzzle in the international finance literature, namely, that exchange rate expectations appear inaccurate and even irrational. We find for a comprehensive dataset that individual forecasters’ performance is skill-based. ‘Superior’ forecasters show consistent ability as their forecasting success holds across currencies. They seem to possess knowledge on the role of fundamentals in explaining exchange rate behavior, as indicated by better interest rate forecasts. Superior forecasters are more experienced than the median forecaster and have fewer personnel responsibilities. Accordingly, foreign exchange markets may function in less puzzling and irrational ways than is often thought.

Contracting Institutions and Development

The quality of contracting institutions has been thought to be of second-order importance next to the impact that good property rights institutions can have on long-run growth. Using a large range of proxies for each type of institution, we find a robust negative link between the quality of contracting institutions and long-run growth when we condition on property rights and a number of additional macroeconomic variables. Although the result remains something of a puzzle, we present evidence which suggests that only when property rights institutions are good do contracting institutions appear also to be good for development. Good contracting institutions can reduce long-run growth when property rights are not secured, presumably because the gains from the (costly) contracting institutions cannot be realised. This suggests that contracting institutions can benefit growth, and that the sequence of institutional change can matter.

Competitive Altruism, Mentalizing and Signalling

The human tendency to cooperate with nonkin even in short-run relationships remains a puzzle. Recently it has been hypothesized that altruism may be a byproduct of “mentalizing”, the process of understanding and predicting the mental states of others. Another idea is based on sexual selection: altruism is a costly signal of good genes. The paper shows that these two arguments are stronger when combined in that altruists who can mentalize have a greater advantage over non-altruists when they can signal their type, even though these signals are costly. Further, once such an equilibrium is established, altruists will not be supplanted by mutants who have similar mentalizing abilities but who lack altruism.

Negative investment in China: financing constraints and restructuring versus growth

This paper attempts to address a puzzle in China’s investment pattern: despite high aggregate investment and remarkable economic growth, negative net investment is commonly found at the microeconomic level. Using a large firm-level dataset, we test three hypotheses to explain the existence and extent of negative investment in each ownership group: what we term the efficiency (or restructuring) hypothesis, the (lack of) financing hypothesis, and the (slow) growth hypothesis. Our panel data probit estimations shows that negative investment by state-owned firms can be explained mainly by inefficiency: owing to over-investment or mis-investment in the past, these firms have had to restructure and to get rid of obsolete capital in the face of increasing competition and hardening budgets. The financing explanation holds for private firms, which have had to divest in order to raise capital. However, rapid economic growth weighs against both effects in all types of firms, with a larger impact for firms in the private and foreign sectors. A tobit model, estimated to examine the determinants of the amount of negative investment, yields similar conclusions.

Environmental Kuznets Curves for Carbon Emissions: A Critical Survey

The empirical finding of an inverse U-shaped relationship between per capita income and pollution, the so-called Environmental Kuznets Curve (EKC), suggests that as countries experience economic growth, environmental deterioration decelerates and thus becomes less of an issue. Focusing on the prime example of carbon emissions, the present article provides a critical review of the new econometric techniques that have questioned the baseline polynomial specification in the EKC literature. We discuss issues related to the functional form, heterogeneity, “spurious” regressions and spatial dependence to address whether and to what extent the EKC can be observed. Despite these new approaches, there is still no clear-cut evidence supporting the existence of the EKC for carbon emissions. JEL classifications: C20; Q32; Q50; O13 Keywords: Environmental Kuznets Curve; Carbon emissions; Functional form; Heterogeneity; “Spurious” regressions; Spatial dependence.Residential satisfaction is often used as a barometer to assess the performance of public policy and programmes designed to raise individuals' well-being. However, the fact that responses elicited from residents might be biased by subjective, non-observable factors casts doubt on whether these responses can be taken as trustable indicators of the individuals' housing situation. Emotional factors such as aspirations or expectations might affect individuals' cognitions of their true residential situation. To disentangle this puzzle, we investigated whether identical residential attributes can be perceived differently depending on tenure status. Our results indicate that tenure status is crucial not only in determining the level of housing satisfaction, but also regarding how dwellers perceive their housing characteristics. Keywords: Housing satisfaction, subjective well-being, homeownership. JEL classification: D1, R2.

Currency Forecast Errors at Times of Low Interest Rates: Evidence from Survey Data on the Yen/Dollar Exchange Rate

Using survey expectations data and Markov-switching models, this paper evaluates the characteristics and evolution of investors' forecast errors about the yen/dollar exchange rate. Since our model is derived from the uncovered interest rate parity (UIRP) condition and our data cover a period of low interest rates, this study is also related to the forward premium puzzle and the currency carry trade strategy. We obtain the following results. First, with the same forecast horizon, exchange rate forecasts are homogeneous among different industry types, but within the same industry, exchange rate forecasts differ if the forecast time horizon is different. In particular, investors tend to undervalue the future exchange rate for long term forecast horizons; however, in the short run they tend to overvalue the future exchange rate. Second, while forecast errors are found to be partly driven by interest rate spreads, evidence against the UIRP is provided regardless of the forecasting time horizon; the forward premium puzzle becomes more significant in shorter term forecasting errors. Consistent with this finding, our coefficients on interest rate spreads provide indirect evidence of the yen carry trade over only a short term forecast horizon. Furthermore, the carry trade seems to be active when there is a clear indication that the interest rate will be low in the future.

Itinéraires : les guides de voyage en Suisse de la fin du XVIIIe siècle à 1914 : contribution à une histoire culturelle du tourisme

Menée dans une approche d'histoire culturelle, cette thèse de doctorat prend pour objet un corpus de guides de voyage en Suisse entre la fin du XVIIIe et le début du XXe siècle. Centrée sur les guides, ces livres qui entretiennent plus que d'autres des liens étroits avec le monde physique, elle a deux grands axes. Le premier est une lecture interdisciplinaire des guides de voyage, qui mêle littérature, bibliographie matérielle, histoire et histoire de l'art. Elle a cherché à comprendre les raisons et logiques du genre, en s'attachant particulièrement à ses fonctions et à ses formes (tant structurelles que textuelles et iconographiques). Cette partie de l'étude est importante, car elle n'a encore jamais été menée. Elle s'articule en deux volets : un volet théorique qui s'intéresse à l'histoire et à la forme des guides de voyage ; et une étude de cas qui s'attache à la lecture plus rapprochée de 6 guides : ceux de Thomas Martyr (1788, 1790 & 1794), Heinrich August Ottokar Reichard (1793 & 1802) et Johann Gottfried Ebel (1793, 1805, 1810-11 & 1817-18) pour la fin du XVIIIe siècle et le tournant du XIXe, et ceux de John Murray (1838 & 1886), Adolphe Joanne (1841, 1865, 1874, 1882 & 1908) et Karl Baedeker (1844, 1852, 1859, 1869, 1876, 1883, 1893, 1901 & 1913) pour le XIXe et la Belle Epoque. Le second axe de cette recherche est une réflexion sur les manières de mettre en scène l'espace dans un texte. En étudiant les itinéraires de voyage en Suisse (mais jusqu'au début du XXe siècle, « la Suisse »est pour les guides de voyage indifféremment un pays et une région supranationale : «les Alpes »), quatre types de mises en forme ont pu être identifiés : le voyage en boucle (linéaire, il part d'un point A pour y revenir), le voyage en marguerite (linéaire avec excursions), le voyage éclaté de l'ordre alphabétique, et enfin le voyage par «routes », fragments d'espace que l'on combine comme les pièces d'un puzzle, créant son chemin au fur et à mesure de sa progression. Ce faisant, on peut affirmer que les guides de voyage modernes (dont la forme se fixe dans les années 1830-1840 avec les premiers Murray, Baedeker et Joanne) se sont construits -malgré tout ce que l'on a pu dire sur la normativité prescriptive du tourisme -autour d'une liberté de plus en plus grande accordée aux voyageurs. Chacune de ces formes et chacun de ces types ayant une histoire et des conditions de possibilités, c'est en s'appuyant sur celles-ci que l'on peut mieux comprendre non seulement l'évolution du voyage et de ses pratiques, mais aussi la constitution de la forme littéraire qui l'a accompagné et permis. Ce faisant, des jalons pour une histoire culturelle du tourisme ont aussi été posés, histoire culturelle que j'appelle maintenant de mes voeux : il est quand même surprenant que, dans le pays de tourisme qu'est la Suisse, quand on s'est jusqu'à présent attaché à l'histoire du tourisme, on n'ait parlé qu'économie, société, infrastructures, loisirs ou santé, voire, plus récemment, écologie et bien-être. Redonner son creuset culturel à ce phénomène, c'est aussi retrouver une part du nôtre, car ces mémoires s'entremêlent indissociablement.

Host innate immune responses to microbial pathogens.

Sepsis is among the leading causes of death worldwide and its incidence is increasing. Defined as the host response to infection, sepsis is a clinical syndrome considered to be the expression of a dysregulated immune reaction induced by danger signals that may lead to organ failure and death. Remarkable progresses have been made in our understanding of the molecular basis of host defenses in recent years. The host defense response is initiated by innate immune sensors of danger signals designated under the collective name of pattern-recognition receptors. Members of the family of microbial sensors include the complement system, the Toll-like receptors, the nucleotide-binding oligomerization domainlike receptors, the RIG-I-like helicases and the C-type lectin receptors. Ligand-activated pattern-recognition receptors kick off a cascade of intracellular events resulting in the expression of co-stimulatory molecules and release of effector molecules playing a fundamental role in the initiation of the innate and adaptive immune responses. Fine tuning of proinflammatory and anti-inflammatory reactions is critical for keeping the innate immune response in check. Overwhelming or dysregulated responses induced by infectious stimuli may have dramatic consequences for the host as shown by the profound derangements observed in sepsis. Unfortunately, translational research approaches aimed at the development of therapies targeting newly identified innate immune pathways have not held their promises. Indeed, all recent clinical investigations of adjunctive anti-sepsis treatments had little, if any, impact on morbidity and all-cause mortality of sepsis. Dissecting the mechanisms underlying the transition from infection to sepsis is essential for solving the sepsis enigma. Important components of the puzzle have already been identified, but the hunt must go on in the laboratory and at the bedside.

Mobile termination, network externalities, and consumer expectations

We re-examine the literature on mobile termination in the presence of network externalities. Externalities arise when firms discriminate between on- and off-net calls or when subscription demand is elastic. This literature predicts that profit decreases and consumer surplus increases in termination charge in a neighborhood of termination cost. This creates a puzzle since in reality we see regulators worldwide pushing termination rates down while being opposed by network operators. We show that this puzzle is resolved when consumers' expectations are assumed passive but required to be fulfilled in equilibrium (as defined by Katz and Shapiro, AER 1985), instead of being rationally responsive to non-equilibrium prices, as assumed until now.

Territorial autonomy and self-determination conflicts: opportunity and willingness cases from Bolivia, Niger, and Thailand

The paradox of autonomy is about whether self-rule accommodates or exacerbates armed conflict. This study attempts to unpack the puzzle examining the effectiveness of territorial autonomy as a state response to self-determination conflicts throughout the world. It challenges the conflict-inducing features of autonomy arguing that territorial autonomy can mitigate armed conflict by channeling group grievances into peaceful forms of protest. Thus, this study aims at arriving at a comprehensive theory that identifies which factors are responsible for violent escalation of conflicts grounded in self-determination demands. By using the concepts of opportunity structures and willingness dimension, this study shows that conflict escalation only takes place when minorities with greater bargaining power vis-à-vis the center, in contexts of high levels of economic inequality within dyad, are mobilized around autonomy and separatist demands.

Repeated Agenda Setting and the Unanimous Approval of Bad Policies

This paper addresses the puzzle of why legislation, even highly inefficient legislation, may pass with overwhelming majorities. We model a egislature in which the same agenda setter serves for two periods, showing how he can exploit a legislature (completely) in the first period by romising future benefits to legislators who support him. In equilibrium, large majority of legislators vote for the first-period proposal because a ote in favor maintains the chance for membership in the minimum winning coalition in the future. The model thus generates situations in which egislators approve policies by large majorities, or even unanimously, that enefit few, or even none, of them. The results are robust: some institutional arrangements, such as super-majority rules or sequential voting, imit but do not eliminate the agenda setter's power to exploit the legislature, and other institutions such as secret voting do not limit his power.

Diagnosing Schistosomiasis

The ideal diagnostic method for schistosomiasis detection seems to be still far from available. Paucity of egg output in low prevalence situations, low levels of circulating antigens in individuals with low intensity of infection and inadequate specificity of antibody detection systems outline pieces of a puzzle that challenges scientific efforts. Estimated prevalence, financial resources and operational reality must be taken into account when deciding the diagnostic method to be used. A combination of a screening step, using a fast strip test for antibody detection with a parasitological ratification step such as Kato-Katz repeated stool examination may serve as a diagnostic approach for a previously untreated low level endemic area. However, when eradication is the aim, and high financial investment is available, re-treatment may be based on the association between multiple stool examination and circulating antigen detection. Ethical aspects as well as cost-benefit rates between treatment and diagnosis approaches lead to the conclusion that in spite of the recent advances in simple administered and relatively safe drugs, treatment should only be performed when supported by appropriated diagnosis

A New open economy macroeconomic model with endogenous portfolio diversification and firms entry

This paper provides a new benchmark for the analysis of the international diversi…cation puzzle in a tractable new open economy macroeconomic model. Building on Cole and Obstfeld (1991) and Heathcote and Perri (2009), this model speci…es an equilibrium model of perfect risk sharing in incomplete markets, with endogenous portfolios and number of varieties. Equity home bias may not be a puzzle but a perfectly optimal allocation for hedging risk. In contrast to previous work, the model shows that: (i) optimal international portfolio diversi…cation is driven by home bias in capital goods, independently of home bias in consumption, and by the share of income accruing to labour. The model explains reasonably well the recent patterns of portfolio allocations in developed economies; and (ii) optimal portfolio shares are independent of market dynamics.