The vanishing procyclicality of labor productivity

We document three changes in postwar US macroeconomic dynamics: (i) theprocyclicality of labor productivity has vanished, (ii) the relative volatility of employment has risen, and (iii) the relative (and absolute) volatility of the real wagehas risen. We propose an explanation for all three changes that is based on a common source: a decline in labor market frictions. We develop a simple model withlabor market frictions, variable effort, and endogenous wage rigidities to illustratethe mechanisms underlying our explanation. We show that the reduction in frictionsmay also have contributed to the observed decline in output volatility.

Economic growth and investment in the Arab world

This paper analyses the economic growth performance in the Arab world overthe last forty years. The Arab world has managed to reduce povertyperformance despite its relatively disappointing growth performance. Werelate this poor performance of both oil and non-oil producers toinvestment. Contrary to widespread belief, we do not find evidence that lowquantity of investment is the main of low growth. The decline in theinvestment rate followed rather than preceded the reduction in the aggregategrowth rate. We conclude that the low quality of investment projects is thekey determinant of growth. The excessive reliance on public investment, thelow quality of financial institutions, the bad business environment (due topolitical and social instability and to excessive public intervention andoverregulation) and the low quality of human capital are importantdeterminants of systematically unproductive investment decisions and, thus,low economic growth.

Specialization and rent-seeking in moral enforcement: The case of confession

Moral codes are produced and enforced by more or less specialized means and are subject to standard economic forces. This paper argues that the intermediary role played by the Catholic Church between God and Christians, a key difference from Protestantism, faces the standard trade-off of specialization benefits and agency costs. It applies this trade-off hypothesis to confession of sins to priests, an institution that epitomizes such intermediation, showing that this hypothesis fits cognitive, historical and econometric evidence better than a simpler rent-seeking story. In particular, Catholics who confess more often are observed to comply more with the moral code; however, no relationship is observed between mass attendance and moral compliance. The data also links the current decline in confession to the rise in education, which makes moral self-enforcement less costly, and to the productivity gap suffered by confession services, given its necessarily interpersonal nature.

On the sources of the Great Moderation

The remarkable decline in macroeconomic volatility experienced by the U.S. economy since the mid-80s (the so-called Great Moderation) has been accompanied by large changes in the patterns of comovements among output, hours and labor productivity. Those changes are reflected in both conditional and unconditional second moments as well as in the impulse responses to identified shocks. That evidencepoints to structural change, as opposed to just good luck, as an explanation for the Great Moderation. We use a simple macro model to suggest some of the immediate sources which are likely to be behindthe observed changes.

The role of Mexico in the first oil shortage: 1918-1922, an international perspective

In 1921 Mexico produced a quarter of world s petroleum, making the country the secondlargest producer in the world, but by 1930 it only accounted for 3 per cent of world sproduction. To date the discussion has mostly relied on events taking place in Mexico forexplaining the decline of the industry. Very little attention has been placed todevelopments in petroleum industry elsewhere, except Venezuela. Practically noattention has been paid to the reasons for the rise of oil output in Mexico. This neglectsthe massive changes taking place in the petroleum industry worldwide during the GreatWar years and its aftermath, and overall ignores the shortage of oil that occurred in theworld s markets between 1918-1921. These are crucial events in order to understand theearly rise of the Mexican oil industry and set the basis for a better understanding of thesubsequent sudden decline.

Irreversible investment in stochastically cyclical markets

This paper presents a new framework for studying irreversible (dis)investment whena market follows a random number of random-length cycles (such as a high-tech productmarket). It is assumed that a firm facing such market evolution is always unsure aboutwhether the current cycle is the last one, although it can update its beliefs about theprobability of facing a permanent decline by observing that no further growth phasearrives. We show that the existence of regime shifts in fluctuating markets suffices for anoption value of waiting to (dis)invest to arise, and we provide a marginal interpretationof the optimal (dis)investment policies, absent in the real options literature. Thepaper also shows that, despite the stochastic process of the underlying variable has acontinuous sample path, the discreteness in the regime changes implies that the samplepath of the firm s value experiences jumps whenever the regime switches all of a sudden,irrespective of whether the firm is active or not.

The impact of women's educational and economic resources on fertility. Spanish birth cohorts 1901-1950

In this chapter we portray the effects of female education and professional achievementon fertility decline in Spain over the period 1920-1980 (birth cohorts of 1900-1950).A longitudinal econometric approach is used to test the hypothesis that the effectsof women s education in the revaluing of their time had a very significant influence onfertility decline. Although in the historical context presented here improvements inschooling were on a modest scale, they were continuous (with the interruption of theCivil War) and had a significant impact in shaping a model of low fertility in Spain. Wealso stress the relevance of this result in a context such as the Spanish for which liberalvalues were absent, fertility control practices were forbidden, and labour forceparticipation of women was politically and socially constrained.

When are layoffs acceptable? Evidence from a quasi-experiment

Many authors have discussed a decline in internal labor markets and an apparent shift to a new employment contract, characterized by less commitment between employer and employee and more portable skills. These discussions occur without much evidence on what employment contract employees currently feel is fair. We perfomed quasi-experimental surveys to study when employees in the U.S. andCanada feel that layoffs are fair.Layoffs were perceived as more fair if they were due to lower product demand than if the result of employee suggestions. This result appears to be solely due to norms of reciprocity (companiesshould not punish employees for their efforts), rather than norms of sharing rents, as new technology was also considered a justification for layoffs.Consistent with theories of distributive and procedural equity, layoffs were perceived as more fair if the CEO voluntarily shared the pain. CEO bonuses due to layoffs lowered their reported fairness only slightly.Respondents in Silicon Valley were not more accepting of layoffsthan were those in Canada on average, although the justificationsconsidered valid differed slightly.

Estat de conservació i propostes de gestió per a Stachys martitima Gouan a la Península Ibèrica

Es documenta la disminució de l’àrea de distribució i del nombre d’individus i s’avalua l’extensió actual d’Stachys maritima a la península Ibèrica, restringida a menys de 200 individus amb una àrea d’ocupació de només 8 km2. L’espècie és requalificada com a CR (en perill crític) en aquest territori, incrementant l’anterior valoració com a VU (vulnerable). Se suggereixen les mesures de conservació adequades que permetin garantir simultàniament activitats de turisme sostenibles

Estudi edàfic dels boscos joves de pi negre del Parc Nacional d'Aigüestortes i Sant Maurici

Estudiem les característiques edàfiques del sòl dels boscos joves de pi negre (Pinus uncinata) de l’estatge subalpí del Parc Nacional d’Aigüestortes i Estany de Sant Maurici corresponents a àrees de reforestació entre els anys 1956 i 2008. Aquest estudi s’ha fet de 29 parcel•les d’aquesta zona situades sobre diferents tipus de substrat, orientació i pendent. S’ha caracteritzat el sòl a partir de l’anàlisi de textura, matèria orgànica, nitrogen total, fòsfor, sodi, potassi, magnesi, calci, capacitat d’intercanvi catiònic, acidesa del sòl, relació C/N. Els resultats confirmen que es tracta de sòls àcids amb un elevat contingut de matèria orgànica a l’horitzó superficial (0-5 cm) i majoritàriament tenen humus de tipus moder. Això fa que aquest tingui valors de nitrogen total elevats. Gràcies al pH àcid i els continguts de potassi, calci i magnesi tindrem una bona fertilitat ja que la solubilitat i assimilació dels nutrients del sòl serà bona. Tots els valors obtinguts disminueixen en profunditat i mostren una gran variabilitat entre les parcel•les estudiades.

Declining labor force attachment and downward trends in unemployment and participation

The US labor market witnessed two apparently unrelated secular movements in thelast 30 years: a decline in unemployment between the early 1980s and the early 2000s,and a decline in participation since the early 2000s. Using CPS micro data and a stock-flow accounting framework, we show that a substantial, and hitherto unnoticed, factorbehind both trends is a decline in the share of nonparticipants who are at the margin ofparticipation. A lower share of marginal nonparticipants implies a lower unemploymentrate, because marginal nonparticipants enter the labor force mostly through unemployment,while other nonparticipants enter the labor force mostly through employment.

Beta cell mass and growth after syngeneic islet cell transplantation in normal and streptozocin diabetic C57BL/6 mice

In islet transplantation, nonimmunological factors such as limited growth capacity or increased death rate could reduce the beta cell mass in the graft and lead to failure of the transplant. We studied the evolution of beta cell replication and mass after transplantation of insufficient, minimally sufficient, or excessive islet tissue. Streptozocin diabetic C57BL/6 mice received 150 or 300 syngeneic islets under the kidney capsule and normal mice received 300 islets. In streptozocin diabetic mice 300 islets restored normoglycemia; beta cell replication in transplanted islets was similar to replication in normal pancreas and beta cell mass in the graft remained constant. In contrast, 150 islets were insufficient to achieve normoglycemia; beta cell replication was increased initially but not by 18 or 30 d despite persistent hyperglycemia, and beta cell mass fell progressively. When islets were transplanted into normal recipients, beta cell replication remained normal but beta cells underwent atrophy and mass in the graft was substantially reduced. Therefore, with a successful islet transplant, in diabetic mice beta cell replication and mass remain constant. In contrast, when insufficient islet tissue is transplanted an initial increase in beta cell replication can not compensate for a decline in beta cell mass. When excessive islet tissue is transplanted, beta cell mass is reduced despite normal beta cell replication.

Top income shares in Portugal over the twentieth century

[cat] L’objectiu d’aquest article és presentar nova evidència estadística sobre l’evolució de les desigualtats econòmiques a Portugal a llarg termini. L’explotació de les fonts fiscals portugueses ha permès l’estimació annual de les top income shares des de 1936. La construcció d’aquesta nova sèrie s’ha fet seguint la metodologia emprada per Piketty (2001). Aquesta nova sèrie revela una caiguda de les top income shares durant la Segona Guerra Mundial, seguida d’una recuperació fins a principis dels anys cinquanta. Des de mitjans dels cinquanta fins a principis dels anys vuitanta hi ha una caiguda dràstica de les top income shares. Per acabar, durant els anys noranta les top income shares tornen a augmentar. Aquesta pauta és molt similar a la viscuda en altres països: la reducció de les top income shares durant l’època daurada és compartida per tots els països estudiats i el seu increment als anys noranta sembla que alinea Portugal amb la pauta seguida pels països Anglosaxons.

Monetary integration and the cost of borrowing

With the beginning of the European Monetary Union (EMU), euro-area sovereign securities¿ adjusted spreads over Germany (corrected from the foreign exchange risk) experienced an increase that caused a lower than expected decline in borrowing costs. The objective of this paper is to study what explains that rising. In particular, if it took place a change in the price assigned by markets to domestic (credit risk and/or market liquidity) or to international risk factors. The empirical evidence supports the idea that a change in the market value of liquidity occurred with the EMU. International and default risk play a smaller role

Evolutionary dynamics of molecular markers during local adaptation: a case study in Drosophila subobscura

Background: Natural selection and genetic drift are major forces responsible for temporal genetic changes in populations. Furthermore, these evolutionary forces may interact with each other. Here we study the impact of an ongoing adaptive process at the molecular genetic level by analyzing the temporal genetic changes throughout 40 generations of adaptation to a common laboratory environment. Specifically, genetic variability, population differentiation and demographic structure were compared in two replicated groups of Drosophila subobscura populations recently sampled from different wild sources. Results: We found evidence for a decline in genetic variability through time, along with an increase in genetic differentiation between all populations studied. The observed decline in genetic variability was higher during the first 14 generations of laboratory adaptation. The two groups of replicated populations showed overall similarity in variability patterns. Our results also revealed changing demographic structure of the populations during laboratory evolution, with lower effective population sizes in the early phase of the adaptive process. One of the ten microsatellites analyzed showed a clearly distinct temporal pattern of allele frequency change, suggesting the occurrence of positive selection affecting the region around that particular locus. Conclusion: Genetic drift was responsible for most of the divergence and loss of variability between and within replicates, with most changes occurring during the first generations of laboratory adaptation. We also found evidence suggesting a selective sweep, despite the low number of molecular markers analyzed. Overall, there was a similarity of evolutionary dynamics at the molecular level in our laboratory populations, despite distinct genetic backgrounds and some differences in phenotypic evolution.