Miracle-dz/UniFAR-FTUs huggingface dataset:
Fortune or Virtue: Time-Variant Volatilities Versus Parameter Drifting in U.S. Data

This paper compares the role of stochastic volatility versus changes in monetary policy rules in accounting for the time-varying volatility of U.S. aggregate data. Of special interest to the authors is understanding the sources of the great moderation of business cycle fluctuations that the U.S. economy experienced between 1984 and 2007. To explore this issue, the authors build a medium-scale dynamic stochastic general equilibrium (DSGE) model with both stochastic volatility and parameter drifting in the Taylor rule and they estimate it non-linearly using U.S. data and Bayesian methods. Methodologically, the authors show how to confront such a rich model with the data by exploiting the structure of the high-order approximation to the decision rules that characterize the equilibrium of the economy. Their main empirical findings are: 1) even after controlling for stochastic volatility (and there is a fair amount of it), there is overwhelming evidence of changes in monetary policy during the analyzed period; 2) however, these changes in monetary policy mattered little for the great moderation; 3) most of the great performance of the U.S. economy during the 1990s was a result of good shocks; and 4) the response of monetary policy to inflation under Burns, Miller, and Greenspan was similar, while it was much higher under Volcker.
Regional Single Currency Effects on Bilateral Trade with the European Union

The regional effects of sharing a single currency on bilateral trade with other European Union member states are a contentious question. This paper examined different definitions along with regional effects of the set of the euro as a common currency by taking advantage of a gravity specification of bilateral trade between the seventeen Spanish regions and EU-13 countries over the period 1997-2004. Our database allows accounting for two distinct definitions of a single currency depending on its temporal set up. That is, the “exchange rate volatility effect” (from exchange rate fixing in 1999) is distinguished from the so-called “common currency effect” (resulting from the issuing of a new currency in 2002). Findings are suggestive of a regional concentration of currency union effects in a few regions, namely those relatively more open to trade, though such effects are found to fade away over time. Trade enhancing effects are found to range between 45 to 16% depending on the specification. Finally, whist the “exchange rate volatility effect” of a common currency was significant, the pure currency union effect was found to be almost negligible.
Do recolonisation processes in intermittent streams have sustained effects on benthic algal density and assemblage composition

When intermittent streams flow, benthic algae develop from both colonising propagules and regrowing dried biofilm. We aimed to determine whether colonisation processes influence algal densities and taxonomic composition beyond the period immediately following commencement of winter flows, and whether regulation modifies those processes, in the Victoria Range, Australia. Stones were placed in two unregulated streams, and upstream and downstream of weirs in three regulated streams, after dry biofilm was removed. Epilithic algae on treatment and control stones were collected after winter flows (12 weeks). Treatment effects were still apparent in one (unregulated) stream, but not in the other streams. Algal assemblages and densities upstream and downstream of weirs differed, but there was no systematic pattern among streams. In intermittent headwater streams, recolonisation processes may influence algal assemblages until spring; but in most streams, the duration of influence will be shorter, depending on the assemblage composition in regrowth and refuges, which is also shaped by conditions during the previous flow season. If the effects of regulation depend on how idiosyncratic flow regimes and assemblage compositions influence recolonisation, they may be difficult to predict. Similarly, recovery trajectories for stream communities after drought will differ among streams, depending on whether biofilm can develop during potentially short seasonal flows.
Equilibrium Counterfactuals

We incorporate structural modellers into the economy they model. Using the traditional moment-matching method, they ignore policy feedback and estimate parameters using a structural model that treats policy changes as zero probability (or exogenous) "counterfactuals. " Estimation bias occurs since the economy's actual agents, in contrast to model agents, understand policy changes are positive probability endogenous events guided by the modellers. We characterize equilibrium bias. Depending on technologies, downward, upward, or sign bias occurs. Potential bias magnitudes are illustrated by calibrating the Leland (1994) model to the Tax Cuts and Jobs Act of 2017. Regarding parameter identification, we show the traditional structural identifying assumption, constant moment partial derivative sign, is incorrect for economies with endogenous policy optimization: The correct identifying assumption is constant moment total derivative sign accounting for estimation-policy feedback. Under this assumption, model agent expectations can be updated iteratively until the modellers' policy advice converges to agent expectations, with bias vanishing.
IFAD IMPACT ASSESSMENT - Irrigated Rice Production Enhancement Project (IRPEP): Philippines

Smallholder rice farming is central to poverty reduction, food security, and rural development in the Philippines. Currently, rice affordability is threatened by the country's protectionist approach to rice imports and low production efficiency. One key issue is that around 41 percent of the country's irrigable land is not irrigated. Moreover, many irrigation systems are suggested to be poorly managed with unequal water distribution. The Irrigated Rice Production Enhancement Project (IRPEP) was implemented in three regions (VI, VII and X) of the Philippines between 2010-2015. It was designed to improve rice productivity and smallholder livelihoods by strengthening canal irrigation infrastructure of Communal Irrigation Systems (CIS), improving the capacity of the Irrigators' Associations (IAs) that manage the CIS, and offering complementary marketing support, Farmer Field Schools, and emergency seed buffer stocks. As the government provides FFS and buffer stocks to farmers across the country, we focus the assessment on the irrigation and marketing activities only. We define the impact indicators based on IRPEP's theory of change, which maps the inputs and activities of the project to outcomes and impacts through various channels. The analysis is based on quantitative data from 2,104 households and 113 IAs covering beneficiary and non-beneficiary groups, along with qualitative data from project and IA staff. We estimate IRPEP's impact by comparing beneficiary and non-beneficiary households and IAs using statistical matching techniques to ensure a clean and unbaised comparison. We then use the qualitative data to try to identify the underlying factors that shaped the results. We particularly focus our analysis on regional heterogeneities in impacts because of the considerable differences between the three project regions. The main difference between regions stems from their varying levels of exposure to extreme weather events (e.g. super typhoons), as Region VIII, and to a lesser extent Region VI, experienced significant extreme weather damage during the project's implementation.
Corporate Governance, Market Discipline, and Productivity Growth

Using a large panel of German manufacturing firms over the years 1986-1996, this study examines the impact of corporate governance and market discipline on productivity growth. We find that firms under concentrated ownership tend to show significantly higher productivity growth. Financial pressure from creditors influences productivity growth positively, particularly for firms in financial distress. Regarding market discipline, productivity grows faster when competition on product markets is intense, but only when owner concentration is high. We do not find evidence that the type of the owner, ownership complexity, or the size of the supervisory board is significantly related to productivity growth.
Planktonic protist communities in a semi-enclosed mariculture pond: structural variation and correlation with environmental conditions

In order to evaluate the environmental status within a mariculture pond, temporal variations of physico-chemical factors, protist community structure and interactions between biota and environmental conditions were investigated during a complete cycle in semi-enclosed shrimp-farming waters near Qingdao, north China. Results revealed that: (1) a total of 54 protist taxa with ten dominant species was present, comprising 4 chlorophyceans, 2 chrysophyceans, 5 cryptophyceans, 10 dinoflagellates, 3 euglenophyceans, 10 diatoms, 18 ciliates and 2 sarcodines; (2) a single peak of protist abundance occurred in October, mainly due to the chlorophyceans, diatoms and chrysophyceans, while the bimodal peaks of biomass in July and October were mainly due to the ciliates, dinoflagellates and diatoms; (3) the succession of protist communities significantly correlated with the changes of nutrients, salinity and temperature, especially phosphate, either alone or in combination with NO3; (4) species diversity and evenness indices were found to be relatively independent of physico-chemical factors, whereas species richness and the ratio of biomass to abundance were strongly correlated with water temperature and abundances of bacteria. It was concluded that planktonic protists are potentially useful bioindicators of water quality in a semi-enclosed mariculture system.
Tax-Induced Inequalities in the Sharing Economy

The growth of sharing economy marketplaces like Airbnb has generated discussions on their socioeconomic impact and lack of regulation. As a result, most major cities in the United States have started to collect an “occupancy tax” for Airbnb bookings. In this study, we investigate the heterogeneous treatment effects of the occupancy tax policy on Airbnb listings, using a combination of a generalized causal forest methodology and a difference-in-differences framework. While we find that the introduction of the tax significantly reduces both listing revenues and sales, more importantly, these effects are disproportionately more pronounced for residential hosts with single shared-space (nontarget) listings versus commercial hosts with multiple properties or entire-space (target) listings. We further show that this unintended consequence is caused by customers’ discriminatory tax aversion against nontarget listings. We then leverage these empirical results by prescribing how hosts should optimally set prices in response to the occupancy tax and identify the discriminatory tax rates that would equalize the tax’s effect across nontarget and target listings. This paper was accepted by Victor Martínez-de-Albéniz, operations management.
The Future of Work in Developing Economies: What can We Learn from the South?

In recent years, there has been an escalation of concern revolving around the effect that automation will have on the future of work. This anxiety has fueled the public and academic debate, fearing that soon this technology will displace jobs at a large scale. Numerous studies have begun to investigate automation’s impact on labor markets, although all have focused on industrialized nations which consist of more service and skilled occupations. Utilizing the World Bank’s STEP Skills Measurement Program Database, we examine automation’s effect on 10 developing countries throughout Latin America, Africa, and Asia. To address the heterogeneity of occupations across the country, we apply a task-based approach and re-calibrate the effect of automation on labor market while analyzing the task structure across countries. Modelling off previous studies, we created an expectation-maximization algorithm to predict the percentage of tasks which are likely to be automated. Jobs whose task automation output was 70% or higher were then considered to be highly automatable. Our results suggest that these developing countries have higher levels of predicted automation risk. Countries range in their level of highly automatable jobs from the lowest being Yunnan – a Chinese province – with 7.7% to the highest of Ghana with 42.4%. We find that occupations containing relatively more routine tasks are more likely to be automated, while workers with a higher level of education reduce their risks. This is the first paper to estimate automation risk rates for developing nations.
Intracellular localization of calcium, phosphorus and nitrogen in common bean seeds (Phaseolus vulgaris L. cv. Borlotto) by SEM, ESI and EELS techniques

ABSTRACT Scanning, transmission electron microscopy, electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS) were used to localize calcium, phosphorus and nitrogen in seeds of Phaseolus vulgaris. Prismatic, straight and kinked twin calcium oxalate crystals were detected in the crystalligen layer of seed teguments. Cytoplasmic calcium and phosphorus-rich particles, probably of phytin, were detected in cotyledon parenchyma cells by ESI and EELS. Moreover, higher levels of calcium were mapped on osmiophilic droplets close to cell walls. Crystals, cytoplasmic phytin particles, osmiophilic droplets and calcium in cell walls disappeared after treatment with critic acid. By chemical assays, 1.1 g/100 g of phytic acid was detected in control seeds, and an 81% decline was observed in citric acid-treated samples. These data suggest that crystals and phytin complexes could play a role in determining the low calcium availability in common beans. Also, nitrogen found in protein bodies of cotyledons could represent an important site of protein reserves.
Granger's Representation Theorem: A Closed-Form Expression for I(1) Processes

The Granger representation theorem states that a cointegrated vector autoregressive process can be decomposed into the four components: a random walk, a stationary process, a deterministic part, and a term that depends on the initial values. In this paper, we present a new proof of the theorem. This proof enables us to derive closed-form expressions of all terms of the representation and allows a unified treatment of models with dierent deterministic specifications. The applicability of our results are illustrated by examples. For example, the closed-form expressions are useful for impulse response analyses and facilitate the analysis of cointegration models with structural changes.
Price Discovery in the Small and in the Large: Momentum and Reversal, Bubbles and Crashes

A discrete-time dynamic asset-pricing model specifies the economic rationale for a rich array of price dynamics. Two boundedly-rational investors with different risk preferences trade periodically, where excess supply is cleared by a tâtonnement. Cast at the core of asset-pricing modelling, this structure allows us to explore price discovery intra-periodically, and over time. If dividends are observable the price converges to Merton’s ICAPM, but if investors rely on past realizations, momentum and reversal patterns emerge, which might escalate to bubbles and crashes. The model features increasing volume but declining liquidity during positive bubbles, and lowest liquidity after negative bubbles.
Big Fish in Small (and Big) Ponds - A Study of Careers

Talented, ambitious workers (big fish) often join highly competitive organizations (big ponds), though they sometimes instead choose less competitive organizations (small ponds) offering brighter promotion prospects. Big fish exist in both types of organizations, though average worker ability is higher in big ponds. Top executives enjoy higher wages in big ponds. Choosing a big pond allows workers to signal high ability. Workers sometimes overestimate or underestimate their abilities, choosing the wrong pond. They also vary in their desire to be promoted. All of the preceding phenomena are shown to be consistent with equilibrium in a new theoretical model of careers.
House Price Convergence in the Euro Zone: A Pairwise Approach

Abstract The adoption of the euro common currency was expected to lead to convergence for a number of economic and financial variables across national borders, including house prices. We apply a probabilistic pairwise approach to the question of whether home values converge across eight euro zone housing markets. Contrary to previous studies, we find only marginal evidence that euro housing markets converge. Moreover, for what convergence there appears to be, there is no evidence that the adoption of the euro itself played a role in creating such convergence. Finally, Germany, the largest and most dominant economy of the currency union, is rarely found to be convergent with other nations.
Links between host-plant type and site of feeding as revealed by the evolution of Palaearctic Eriococcidae (Sternorrhyncha: Coccoidea)

Abstract This work is an assessment of the biogeographical, taxonomic, biological and phylogenetic knowledge of the poorly defined family Eriococcidae. The study of its geographical diversity shows the richness of the Palearctic fauna on which the present analysis focuses. The numerous systems dealing with the taxonomy of Eriococcidae are detailed, and the specific taxonomical status of the genus Eriococcus, which contains 155 out of the 175 known Palearctic species is reevaluated. The phylogeny of the palaearctic members of the scale insect family Eriococcidae is reconstructed, using 9 genera and 52 species. Three more scale insect species belonging to 3 families were used as outgroups. The cladistic analysis of 130 morphological characters of the adults resulted in 10 most parsimonious trees, placing Eriococcus buxi as the sister-group of all other sampled Eriococcidae. The genera Acanthococcus, Rhizococcus, Greenisca and Anophococcus appear as para- or polyphyletic, but the weakness of most of the clades does not allow to denounce strictly the monophyly of these genera. However, some clades are supported with high confidence, like (Kaweckia + Neokaweckia), (Anophococcus parvispinus(Anophococcus inermis+Greenisca placida) and (Gossyparia spuria+Acanthococcus aceris). Concerning host-plant relationships, the phylogeny supports an evolutionary scenario whereby the ancestor of the family Eriococcidae fed originally on woody plants, and more typically on leaves. The switch observed from Poaceae to other herbaceous plants is correlated to the switch from leaves as preferred site of nutrition to branches and stems. The supported scenario shows another switch, back from other herbs to Poaceae, associated to the choice of leaves as nutrition site.
Reproductive Investment and Growth History in Female Coho Salmon

Abstract The body size, ovary mass, egg mass, and fecundity of coho salmon Oncorhynchus kisutch from three different rearing environments (wild, ranched, and captive) were compared to determine which aspects of growth history affect changes in these reproductive characters. In addition, the growth of individually tagged females reared in captivity throughout the seawater growth phase was measured and related to final reproductive investment. A strong positive relationship existed between ovary mass and body length at spawning; this relationship was maintained over a wide range of final body sizes, and the regression slope was consistent among the rearing environments. However, the relative investment in ovary mass and fecundity (regression intercepts) differed between rearing environments. Fish reared in captivity throughout their life cycle had higher values than did fish reared in the other two environments. A relatively weak positive relationship between egg mass and final body length was common to fem.
Characterisation of Self-Employment in Spain. An Analysis from the Gender Perspective

The growing presence of women on the Spanish labour market in the last few decades has revealed gender inequalities that affect both participation indicators such the activity or unemployment rate, and working conditions (working hours, contract duration, salaries, etc.). There are also inequalities in self-employment. This research identifies and tests the existence of different personal and occupational characteristics, including previous occupation in the entrepreneurial sector and else, of self-employed individuals in Spain. The results show that there are characteristics that distinguish self-employed entrepreneurship the perspective of gender, such as level of education, instability in working history, the sector concerned and cumulative experience in that sector. This enables us to identify specific profiles for men and women, and highlights the convenience of designing activities differentiated by gender for promoting entrepreneurship.
Second-Mover Advantage and Price Leadership in Bertrand Oligopoly

We consider the issue of first versus second-mover advantage in differentiated-product Bertrand duopoly with general demand and asymmetric linear costs. We generalize existing results for all possible combinations where prices are either strategic substitutes and/or complements, dispensing with common extraneous assumptions. We show that a firm with a sufficiently large cost lead over its rival has a first mover advantage. For the linear version of the model, we invoke a natural endogenous timing scheme coupled with equilibrium selection according to risk-dominance. This yields sequential play with the low-cost firm as leader as the unique equilibrium outcome.
Risk-Based Portfolio Optimization in the Cryptocurrency World

This study explores the performance of seven state-of-the-art risk-based portfolio optimization strategies from the perspective of a cryptocurrency investor. Analyzing the inverse volatility, minimum variance, l2-norm constrained minimum variance, l2-norm constrained maximum decorrelation, maximum diversification and risk parity portfolio, we find that most strategies systematically outperform individual cryptocurrencies and the equally-weighted benchmark portfolio. Further, a bull and bear market performance comparison as well as tail, extreme risk, and diversification analyses reveal that these strategies provide significant downside risk reduction. The results are robust to using different estimation windows, rebalancing periods and covariance estimation methodologies. Finally, our empirical results indicate that the maximum decorrelation portfolio is the worst strategy in terms of risk-adjusted return, while the long-only minimum variance portfolio is the best performing strategy.
Influence of ground cover on beneficial arthropods in pecan.

Abstract Arthropods were collected, identified, and counted on three dates to determine the effects of ground cover on arthropod type and density in pecan canopies. Ground covers were a grass sod (primarily bermudagrass,Cynodon dactylon[L.] Pers.), red clover (Trifolium pratenseL.), or a mixture of crimson clover (T. incarnatumL.) and hairy vetch (Vicia villosaRoth.). Arthropods collected represented eight orders of Insecta, three orders of Arachnida, and one Chilopoda. Ground cover had little effect on the density or type of arthropods present in the pecan canopy, except that densities ofChrysoperla rufilabris(Burmeister) were greater during July from pecans with a legume ground cover than from those with a grass ground cover.Chrysoperla rufilabrisis a major predator of aphids, which may suppress pecan aphid density. Other statistically significant differences in arthropod density between ground cover types were not of practical importance.