Modeling Sample Selection for Durations with Time-Varying Covariates, With an Application to the Duration of Exchange Rate Regimes

We extend existing estimators for duration data that suffer from non-random sample selection to allow for time-varying covariates. Rather than a continuous-time duration model, we propose a discrete-time alternative that models the effects of sample selection at the time of selection across all subsequent years of the resulting spell. Properties of the estimator are compared to those of a naive discrete duration model through Monte Carlo analysis and indicate that our estimator outperforms the naive model when selection is non-trivial. We then apply this estimator to the question of the duration of monetary regimes and find evidence that ignoring selection into pegs leads to faulty inferences.exchange rates; de facto regimes; duration; selection models; monetary policy

Foreign Currency Debt, Financial Crises and Economic Growth: A Long Run View

Foreign currency debt is widely believed to increase risks of financial crisis, especially after being implicated as a cause of the East Asian crisis in the late 1990s. In this paper, we study the effects of foreign currency debt on currency and debt crises and its indirect effects on short-term growth and long-run output effects in both 1880-1913 and 1973-2003 for 45 countries. Greater ratios of foreign currency debt to total debt is associated with increased risks of currency and debt crises, although the strength of the association depends crucially on the size of a country’s reserve base and its policy credibility. We found that financial crises, driven by exposure to foreign currency, resulted in significant permanent output losses. We estimate some implications of our findings for the risks posed by currently high levels of foreign currency liabilities in eastern Europe.foreign currency debt, currency crises, sudden stops, financial development

Political Elites in Federalized Countries: The Case of Spain (1980-2005). CES Working Paper, no. 146, 2008

This paper explores the social profile of the regional elite that has emerged in Spain since the de-mocratization and federalization of the country. For the first time, researchers present data about crucial variables like gender, place of birth, age, education, and profession. They make inter-regional comparisons, put their data on an international perspective, and try to explain some un-expected findings, such as the behavior of political elites in Catalonia and Castile-La Mancha. The authors compare also the social profile of MPs of the two largest parties and show that the gap between society and political elite has been reduced over the years. The paper offers a research agenda

Exchange-Rate Regimes and International Trade: Evidence from the=20 Classical Gold Standard Era

In this paper we show that the spread of the classical gold=20 standard in the late nineteenth century increased international trade=20 flows. This positive effect was compounded whenever a group of countries=20 formed a monetary union. Applying the gravity model of trade to more than=20 1,100 country pairs during the 1870-1910 period, we find that two countries= =20 on gold would trade 60 percent more with each other than with countries on= =20 a different monetary standard. Moreover, a monetary union would more than=20 double bilateral trade flows. Our findings are relevant for current=20 discussions on alternative monetary arrangements for the twenty-first= century.

Political elites in federalized countries : the case of Spain (1980-2005)

This paper explores the social profile of the regional elite that has emerged in Spain since the federalization of the State. For the first time, researchers present data about crucial variables like gender, place of birth, age, education, and profession. They make interregional comparisons, and try to explain some unexpected findings like the behavior of political elites in some regions like Catalonia. The authors compare also the social profile of MPs of the two largest parties

Quantum horizons and black hole entropy: Inclusion of distortion and rotation

Equilibrium states of black holes can be modelled by isolated horizons. If the intrinsic geometry is spherical, they are called type I while if it is axi-symmetric, they are called type II. The detailed theory of geometry of \emph{quantum} type I horizons and the calculation of their entropy can be generalized to type II, thereby including arbitrary distortions and rotations. The leading term in entropy of large horizons is again given by 1/4th of the horizon area for the \emph{same} value of the Barbero-Immirzi parameter as in the type I case. Ideas and constructions underlying this extension are summarized.Comment: 9 page

Microwave-assisted synthesis of layered basic zinc acetate nanosheets and their thermal decomposition into nanocrystalline ZnO

We have developed a low-cost technique using a conventional microwave oven to grow layered basic zinc acetate (LBZA) nanosheets (NSs) from a zinc acetate, zinc nitrate and HMTA solution in only 2 min. The as-grown crystals and their pyrolytic decomposition into ZnO nanocrystalline NSs are characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD) and photoluminescence (PL). SEM and AFM measurements show that the LBZA NSs have typical lateral dimensions of 1 to 5 μm and thickness of 20 to 100 nm. Annealing in air from 200°C to 1,000°C results in the formation of ZnO nanocrystalline NSs, with a nanocrystallite size ranging from 16 nm at 200°C to 104 nm at 1,000°C, as determined by SEM. SEM shows evidence of sintering at 600°C. PL shows that the shape of the visible band is greatly affected by the annealing temperature and that the exciton band to defect band intensity ratio is maximum at 400°C and decreases by a factor of 15 after annealing at 600°C. The shape and thickness of the ZnO nanocrystalline NSs are the same as LBZA NSs. This structure provides a high surface-to-volume ratio of interconnected nanoparticles that is favorable for applications requiring high specific area and low resistivity such as gas sensing and dye-sensitized solar cells (DSCs). We show that resistive gas sensors fabricated with the ZnO NSs showed a response of 1.12 and 1.65 to 12.5 ppm and 200 ppm of CO at 350°C in dry air, respectively, and that DSCs also fabricated from the material had an overall efficiency of 1.3%

Preliminary report on osteochondrosis in cattle in the north-western parts of South Africa

The north-western part of South Africa, in particular, is well known for mineral imbalances. Aphosphorosis, resulting in rickets and osteomalacia, received a lot of attention at the turn of the nineteenth century (1882–1912). This was followed in 1997 by research on Vryburg hepatosis, another area-specific mineral imbalance–related disease in young calves reared on manganese-rich soil derived from the weathering of dolomitic (carbonate) rock formations. In 1982, a totally new syndrome (osteochondrosis) manifested in, amongst others, areas in South Africa where aphosphorosis was rife. Osteochondrosis was also identified in the south-western parts of Namibia as well as southern Botswana and other areas in South Africa. Osteochondrosis has a multifactorial aetiology and this study focused on the role of minerals, particularly phosphorus, in the development of the disease. A significant improvement in the clinical signs in experimental animals and a reduction of osteochondrosis occurred on farms where animals received bioavailable trace minerals and phosphorus as part of a balanced lick. An increase in the occurrence of the disease on farms during severe drought conditions in 2012–2013 prompted researchers to investigate the possible role of chronic metabolic acidosis in the pathogenesis of the disease.http://www.ojvr.org/am2016Paraclinical Science

Lexical access speed and the development of phonological recoding during immediate serial recall

A recent Registered Replication Report (RRR) of the development of verbal rehearsal during serial recall revealed that children verbalized at younger ages than previously thought, but did not identify sources of individual differences. Here, we use mediation analysis to reanalyze data from the 934 children ranging from 5 to 10 years old from the RRR for that purpose. From ages 5 to 7, the time taken for a child to label pictures (i.e. isolated naming speed) predicted the child’s spontaneous use of labels during a visually presented serial reconstruction task, despite no need for spoken responses. For 6- and 7-year-olds, isolated naming speed also predicted recall. The degree to which verbalization mediated the relation between isolated naming speed and recall changed across development. All relations dissipated by age 10. The same general pattern was observed in an exploratory analysis of delayed recall for which greater demands are placed on rehearsal for item maintenance. Overall, our findings suggest that spontaneous phonological recoding during a standard short-term memory task emerges around age 5, increases in efficiency during the early elementary school years, and is sufficiently automatic by age 10 to support immediate serial recall in most children. Moreover, the findings highlight the need to distinguish between phonological recoding and rehearsal in developmental studies of short-term memory