Miracle-dz/UniFAR-FTUs huggingface dataset:
Blinded by the light? Heterogeneity in the luminosity-growth nexus and the African growth miracle

Night-time light emissions are a popular proxy for growth in circumstances where official data are deemed unreliable. We show that the underlying relationship varies substantially across countries, undermining the imposition of a single slope common in the literature. We propose a two-step method to improve country-specific growth estimates informed by night-light data, making use of a machine-learning algorithm to discern factors driving differences in the luminosity-growth elasticity across countries. The improved performance of this strategy over existing approaches is established in a number of simulation exercises. Applied to African data between 1992 and 2013 we find little evidence of an `African Growth Miracle' undetected by official statistics, as suggested by Young (2012); instead, we observe that countries which recently revised their GDP figures tend to report substantially inflated growth rates over recent years, in line with Jerven (2014)'s hypothesis of purely `statistical growth'.
Preference Reversal

Preference reversal concerns a systematic divergence between prices of lotteries and subjects' expressed preferences for playing the respective lotteries. This article surveys the discovery of preference reversal by psychologists, its re-examination and corroboration both by psychologists and later on by (first sceptical) economists, as well as the causes of preference reversal. The preference reversal phenomenon has been explained to be caused by four determinants, viz. by the mode of elicitation of certainty equivalents, by intransitivity of preferences, by overpricing and/or underpricing of lotteries, and by nonlinear probabilities.
Numerical simulation of secondary flow in pneumatic conveying of solid particles in a horizontal circular pipe

Under certain conditions, a fully developed turbulent flow in a straight pipe may show a secondary flow; for instance, when non-circular cross-section or non-uniform wall roughness around the perimeter of the duct are considered. In horizontal pipe particle-laden gas flow, the non-uniform forcing of the flow by the solids entrained in the gas core may also drive a secondary flow, even with uniform wall roughness along the circumferential direction. In this paper, the effects of wall roughness, particle size and particle mass loading ratio on the secondary flow developing in a horizontal pipe of circular cross-section under turbulent conditions are analysed. The computations are based on the Euler-Lagrange approach accounting for wall roughness and inter-particle collisions (i.e., four-way coupling). In the case of inertial particles, if inter-particle collisions are disregarded, the secondary flow consists of two recirculation cells with an upward flow near the vertical (symmetry) axis and a downward flow close to the walls. On the other hand, when inter-particle collisions are accounted for, the pattern depends on the particle concentration profile: with relatively smooth walls (low roughness), two recirculation cells are found, but with rough walls four recirculation cells are generated. For smaller particles, a transition between two and four recirculation cells in the secondary flow is observed by increasing the mass loading ratio.
Explorer Accelerating Asynchronous Stochastic Gradient Descent for Neural Machine Translation

In order to extract the best possible performance from asynchronous stochastic gradient descent one must increase the mini-batch size and scale the learning rate accordingly. In order to achieve further speedup we introduce a technique that delays gradient updates effectively increasing the mini-batch size. Unfortunately with the increase of mini-batch size we worsen the stale gradient problem in asynchronous stochastic gradient descent (SGD) which makes the model convergence poor. We introduce local optimizers which mitigate the stale gradient problem and together with fine tuning our momentum we are able to train a shallow machine translation system 27% faster than an optimized baseline with negligible penalty in BLEU.
Choosing Democracy

In an autocracy, the ruling elite allocates resources to unproductive contest in order to protect its power. This paper establishes that a flatter income distribution, a slow-growing or shrinking capital stock, and a decrease in the relative size of the workforce increases the likelihood of a decision by the ruling elite to negotiate a transition to democracy. In a model of economic cooperation and political conflict, the losses from ceding control over the tax rate may be lower than the costs of defending minority privilege. The predictions are evaluated in the light of the South African and other recent transitions.
Financial Technology , Unpredictability and Illiquidity in the Long Run

In most sectors, technological progress boosts efficiency. But financial technology and the associated data-intensive trading strategies have been blamed for market volatility, illiquidity and inefficiency. We adopt the lens of growth theory and point it at the financial economy to understand how technological progress in data processing might shape financial activity. When the financial sector becomes more efficient at processing data, it alters the value of information about future dividends (fundamentals) relative to the value of information about order flow (non fundamental trading). Thus unbiased technological change can explain why financial analysis has shifted from primarily investigating the fundamental profitability of firms to primarily acquiring and processing client order flow data. Growth in financial technology can also reconcile two seemingly contradictory trends in asset markets: the increase in price informativeness and the stagnation of market liquidity. ∗Princeton University; farboodi@princeton.edu †Department of Economics Stern School of Business, NBER, and CEPR, New York University, 44 W. 4th Street, New York, NY 10012; lveldkam@stern.nyu.edu; http://www.stern.nyu.edu/∼lveldkam. ‡We thank Markus Brunnermeier, Martin Eichenbaum, Sergio Rebelo, Steven Strongin and Xavier Vives, as well as participants at the LAEF conference on information in finance for comments and Goldman Sachs for their financial support through the GMI Fellowship program. We thank John Barry, Chase Coleman, Roxana Mihet and Arnav Sood for their capable research assistance. JEL codes:
VEC a semantic search engine for tagged artworks based on word embeddings

This bachelor thesis reports on the implementation of a semantic search engine based on word embeddings. The dataset comes from the ARTigo ecosystems, which comprises at the same time a tagging system (folksonomy) and a search engine for images of artworks. Word/document embeddings consist of a technique for representing a textual document as a vector of real numbers. The basic premise of word embeddings is that words or documents which appear in similar contexts are represented by similar vectors. In the course of this thesis, the two word embediding techniques word2vec and doc2vec were both trained and evaluated in order to creating a semantic artwork search engine for the ARTigo dataset, namely art2vec. Many word embedding techniques rely on deep learning models based on neural networks. Almost all of word2vec’s hyper-parameters were experimented and refined with the focus on improving the recall for search queries, i.e. finding artworks not explicitly tagged with the queried search terms. Word2vec and doc2vec include two different algorithms for training the embeddings, which are differently suited for dissimilar tasks. Both a vector representation and a simpler synonym list generation approach were experimented. Considering various semantic aspects, the quality of the semantic similarity between words and documents that are extracted from the embeddings were evaluated. So that these document vectors can be integrated into a search engine, an algorithm for generating query vectors from ARTigo’s search queries is presented in this thesis. Finally, an evaluation by users is reported about the recall improvements resulted from each of the applied word embedding approaches. Word2vec’s averaged word vectors outperformed the other two approaches in all tag categories evaluated. Indeed good results were achieved only for surface (67.90%) and deep semantics (77.16%) tags. So that specially long queries can offer a good retrieval quality, in future work word2vec parameters have to be refined again and the developed query vector algorithm must be polished.
Observations of chorus at Saturn using the Cassini Radio and Plasma Wave Science instrument

[1] Observations at Saturn of whistler mode chorus emissions have been obtained by the Cassini Radio and Plasma Wave Science instrument. Data from the first 45 orbits are analyzed, and the characteristics of the chorus emissions are discussed. Wave normal and Poynting vector measurements from the five-channel waveform receiver are used to examine the propagation characteristics of the chorus, and high-resolution measurements from the wideband receiver are used to examine the fine structure. At Saturn, two different types of chorus are detected. The most common observations are of chorus propagating away from Saturn’s magnetic equator, suggesting a source near the magnetic equator. This chorus is usually detected for many hours, is only observed below half the electron cyclotron frequency, and occurs primarily from L shells of about 5 to 8, and the occurrence of the emission shows no obvious correlation with Saturn magnetic latitude, longitude, or local time. The high-resolution measurements show that the fine structure of this chorus typically consists of larger time scale features (many seconds to minutes) than detected at the Earth (<1 s). The second region of chorus detected at Saturn is in association with local plasma injections. For many of the plasma injection events, chorus emissions are detected both above and below half the electron cyclotron frequency, with a gap in the emission at half the cyclotron frequency. This chorus also shows fine structure at smaller time scales (<1 s to a few seconds), and the overall structure of this chorus appears more similar to chorus detected at the Earth.
The Effects of Firms' Lobbying on Resource Misallocation

We study the causal effect of firms’ lobbying activities on the misallocation of resources through the distortion of firm size. To address the endogeneity between firms’ lobbying expenditure and their size, we propose a new instrument. Specifically, we measure firms’ political connections based on the geographic proximity between their headquarter locations and politicians’ districts in the U.S., and trace the value of these networks over time by exploiting politicians’ assignment to congressional committees. We find that a 10 percent increase in lobbying expenditure leads to a 3 percent gain in revenue. To investigate the macroeconomic consequences of these effects, we develop a heterogeneous firm-level model with endogenous lobbying. Using a novel dataset that we construct, we document new stylized facts about lobbying behavior and use them, including the one from the instrument, to estimate the model. Our counterfactual analysis shows that the return to firms’ lobbying activities amounts to a 22 percent decrease in aggregate productivity in the U.S.
On the Out-of-Sample Importance of Skewness and Asymmetric Dependence for Asset Allocation

Recent studies in the empirical finance literature have reported evidence of two types of asymmetries in the joint distribution of stock returns. The Þrst is skewness in the distribution of individual stock returns, while the second is an asymmetry in the dependence between stocks: stock returns appear to be more highly correlated during market downturns than during market upturns. In this paper we examine the economic and statistical significance of these asymmetries for asset allocation decisions in an out-of-sample setting. We consider the problem of a CRRA investor allocating wealth between the risk-free asset, a small-cap and a large-cap portfolio, using monthly data. We use models that can capture time-varying means and variances of stock returns, and also the presence of time-varying skewness and kurtosis. Further, we use copula theory to construct models of the time-varying dependence structure that allow for greater dependence during bear markets than bull markets. The importance of these two asymmetries for asset allocation is assessed by comparing the performance of a portfolio based on a normal distribution model with a portfolio based on a more sexible distribution model. For a variety of performance measures and levels of risk aversion our results suggest that capturing skewness and asymmetric dependence leads to gains that are economically signiÞcant, and statistically significant in some cases.
Benin

The Public Investment Management Assessment (PIMA) of Benin has brought to light an institutional framework of high quality but ineffective implementation. In accordance with the PIMA methodology applied in several countries, the mission focused on assessing the institutional strengths (such as the legal framework and organization) for each institution in the analytical framework, as well as its effective implementation. Benin was found to have a high-quality, relatively complete institutional framework. The country outperforms its peers in this regard, not only compared with the average for the countries of the subregion (the West African Economic and Monetary Union—WAEMU), but also the Sub-Saharan African countries that have already conducted a PIMA exercise (Figure 1). The effectiveness of the framework, however, is weak.
If I'm Not Hot, are You Hot or Not? Physical Attractiveness Evaluations and Dating Preferences as a Function of Own Attractiveness

Prior research has established that people's own physical attractiveness affects their selection of romantic partners. The current work provides further support for this effect and also examines a different yet related question: when less attractive people accept less attractive dates, do they persuade themselves that those they choose to date are more physically attractive than others perceive them to be? Our analysis of data from the popular website HOTorNOT.com suggests that this is not the case: less attractive people do not delude themselves into thinking that their dates are more physically attractive than others perceive them to be.
The significance of VLF transmitters in the precipitation of inner belt electrons

From the low-altitude satellite P78-1, narrow and sometimes multiple peaks have been observed in the energy spectra of electrons from 68 to 1120 keV precipitating in the drift loss cone from the inner radiation belt. Simultaneously, measurements of the plasma wave environment at higher altitudes on the same field lines have been made with the ISEE plasma wave experiment in many cases. The peaks in electron energy are sometimes extremely narrow, being of the order of 20-keV wide after the instrument resolution is unfolded. The plasma wave observations in these cases reveal the frequent presence of single and sometimes multiple monochromatic frequencies in the 10 kHz to 25-kHz range that are attributed to ground-based VLF transmitters. The plasma wave experiment also provides electron plasma density profiles. The variations of the peak energies with L value and the nearly simultaneous and spatially coordinated narrow band wave frequencies strongly support the conclusion that the narrow peaks in the electron spectra result from cyclotron resonance interactions with the waves produced by ground-based VLF transmitters and that the effects of two or more transmitters are sometimes observed simultaneously.
Classification of collective modes in a charge density wave by momentum-dependent modulation of the electronic band structure

We present time- and angle-resolved photoemission spectroscopy (trARPES) measurements on the charge density wave system CeTe3. Optical excitation transiently populates the unoccupied band structure and reveals a gap size of 2� = 0.59 eV. The occupied Te-5p band dispersion is coherently modified by three modes at
What Lies Behind Income Mobility? Reranking and Distributional Change in Belgium, Western Germany and the USA

The paper presents a decomposition of income mobility indices into two basic sources: mobility induced by a change of the income distribution shape, and mobility induced by a reordering of individuals in the income pecking order. The decomposition procedure, based on counterfactual distributions, results in a decomposition that is applicable to a broad class of mobility measures. Application to income 'movement' indices with data for Belgium, Western Germany and the USA indicates that reranking has been the major force behind income mobility.
Uncovering Female Child Sexual Offenders—Needs and Challenges for Practice and Research

This article provides a short literature overview on female child sexual offenders (FCSO) focusing on the discrepancy between prevalence rates from different sources, characteristics of FCSO and their victims, as well as the societal “culture of denial” surrounding these women. FCSO are a powerful social taboo. Even professionals in the healthcare or justice system were shown to respond inappropriately in cases of child sexual abuse committed by women. As a result, offences of FCSO may be underreported and therefore difficult to research. The lack of scientific data on FSCO lowers the quality of child protection and treatment services. We therefore deem it particularly necessary for professionals in health care to break the social taboo that is FCSO and to further stimulate research on the topic of FCSO. We provide some general implications for professionals in health care systems as well as specific recommendations for researchers. We end with an overall conclusion.
Why are Americans Addicted to Baseball? An Empirical Analysis of Fandom in Korea and the U.S.

Theories of rational addiction posit that certain habit-forming goods - characterized by an increasing marginal utility of consumption - generate predictable dynamic patterns of consumer behavior. It has been suggested that attendance at sporting events represents an example of such a good, as evidenced by the pricing strategies of commercial sports interests. In this essay, we provide new evidence in support of rational addiction for the case of Major League Baseball, but fail to find such support in data from the Korean Professional Baseball League. We then review the scientific literature on sports fans from the perspective of human behavioral ecology and propose a theory of endogenous habit formation among sports fans that could explain our findings.
Re-evaluation of the probabilities for productive rearrangements on the κ andλloci

V-J rearrangements at Ig light chain (IgL) genes occur in resting small pre-B cells. In the absence of cell division, the probability of productive K and X rearrangements is proportional to the output of K+ B and X+ B cells in bone marrow. The kinetics and probability of productive K or X rearrangements was assessed in three groups of mice carrying two (wild-type), one or no intact Igtc gene, and the following conclusion are drawn, K and X rearrangements occur independently at different kinetics, and rearrangements are initiated at a time when K rearrangements are stopping. The probability of productive K and X rearrangements per chromosome is calculated to be -60 and -20% respectively. Thus, a K gene can attempt rearrangements up to three times per chromosome during B cell development. These findings explain that the observed ratio of K+ BIX+ B cell production in wild-type mice is 95/5.
Coupled Re-Os and U-Pb geochronology of the Tonian Chuar Group, Grand Canyon.

Well-preserved strata of the late Tonian Chuar Group exposed in the Grand Canyon host fossil evidence for the development of eukaryotic predation, the presence of unique biomarkers, and large changes in C, S, and Mo isotope chemostratigraphy. Despite the importance of this critical succession, few radioisotopic age constraints are available to place these records into a global context. Here, we couple high-precision U-Pb chemical abrasion−isotope dilution−thermal ionization mass spectrometry (CA-ID-TIMS) on zircon crystals with the rhenium-osmium (Re-Os) sedimentary and sulfide geochronometer to refine the temporal framework of this pivotal interval of Earth history. Zircons recovered from a tuff within the uppermost Walcott Member of the Kwagunt Formation yield a weighted mean 206Pb-238U age of 729.0 ± 0.9 Ma (mean square of weighted deviates [MSWD] = 0.86), differing significantly from the previous air-abrasion upper-intercept age of 742 ± 6 Ma on zircons from this same horizon. Organic-rich carbonates from the Carbon Canyon Member of the Galeros Formation yield a model 1 Re-Os age of 757.0 ± 6.8 Ma (MSWD = 0.47, n = 8), and an initial Os isotope (187Os/188Os [Osi]) composition of 1.13 ± 0.02. The radiogenic Osi value from this horizon suggests that the basin was restricted from the open ocean during deposition of the Carbon Canyon Member, in agreement with sedimentological and stratigraphic data. The Re-Os geochronology of marcasite (FeS2) nodules from the Awatubi Member of the Kwagunt Formation yield a model 1 age of 751.0 ± 7.6 Ma (MSWD = 0.37, n = 5), with an Osi of 0.44 ± 0.01. This Re-Os date is interpreted to constrain the growth of the marcasite nodules in the Awatubi Member during deposition. The formation of sulfides and the less radiogenic Osi value are consistent with an influx of sulfate-laden seawater to the basin during deposition of the Kwagunt Formation. Attempts to apply the Re-Os geochronometer to the Walcott and Tanner Members of the Chuar Group failed to yield meaningful ages, despite elevated Re enrichments (>20 ng/g). The Re-Os data from these units yielded negative Osi values, which suggest disturbance to the Re-Os system. The low Os abundances (typically <100 pg/g) relative to the amount expected based on the elevated Re abundances suggest leaching of Os due to oxidative weathering on geologically recent time scales. Finally, the Carbon Canyon Member provides a useful case study for quantifying how input uncertainties in the Re-Os geochronometer propagate into the resulting age uncertainty, and we discuss the protocols that will yield the best improvement in age precision for future studies. The U-Pb and Re-Os geochronology presented here illustrates the power of coupling these systems and the importance of recent improvements in both methods. Our analysis suggests that for our data, the most efficient way of reducing uncertainties in the presented Re-Os dates is through improved precision of measured Os values.
The Structure of Wages in the Netherlands, 1986-98

For many OECD countries an increase in wage inequality has been documented since the early 1980s. This is often attributed to a general rise in the demand for skilled workers resulting from recent technological change. Using the Organization for Strategic Labour Market Research (OSA) Labour Supply data, this paper studies the wage structure in the Netherlands over the period 1986-98 and demonstrates that wage inequality did not increase to any significant extent in the Netherlands. Using the accounting framework proposed by Juhn et al. (Journal of Political Economy 101: 410-442, 1993), it is shown that the relatively stable wage structure until at least the late 1990s can be attributed mainly to returns to observable components, such as education and experience, while residual wage inequality is found to be of minor importance in explaining the Dutch wage structure. These estimates suggest that the demand for skill in the Netherlands is likely not to have been rising to the extent it did in many other countries over this period.