A semiparametric model for heterogeneous panel data with fixed effects

© 2015 Elsevier B.V. All rights reservedfor semiparametric panel data models in a setting where both the time series and the cross section are large. Such settings are common in finance and other areas of economics. Our model allows for heterogeneous nonparametric covariate effects as well as unobserved time and individual specific effects that may depend on the covariates in an arbitrary way. To model the covariate effects parsimoniously, we impose a dimensionality reducing common component structure on them. In the theoretical part of the paper, we derive the asymptotic theory for the proposed procedure. In particular, we provide the convergence rates and the asymptotic distribution of our estimators. In the empirical part, we apply our methodology to a specific application that has been the subject of recent policy interest, that is, the effect of trading venue fragmentation on market quality. We use a unique dataset that reports the location and volume of trading on the FTSE 100 and FTSE 250 companies from 2008 to 2011 at the weekly frequency. We find that the effect of fragmentation on market quality is nonlinear and non-monotonic. The implied quality of the market under perfect competition is superior to that under monopoly provision, but the transition between the two is complicated

A Discrete Choice Model For Large Heterogeneous Panels with Interactive Fixed Effects with an Application to the Determinants of Corporate Bond Issuance

What is the effect of funding costs on the conditional probability of issuing a corporate bond? We study this question in a novel dataset covering 5610 issuances by US firms over the period from 1990 to 2014. Identification of this effect is complicated because of unobserved, common shocks such as the global financial crisis. To account for these shocks, we extend the common correlated effects estimator to settings where outcomes are discrete. Both the asymptotic properties and the small sample behavior of this estimator are documented. We find that for non-financial firms, yields are negatively related to bond issuance but that effect is larger in the pre-crisis period

Partial level density of the n-quasiparticle excitations in the nuclei of the 39< A <201 region

Level density and radiative strength functions are obtained from the analysis of two-step cascades intensities following the thermal neutrons capture. The data on level density are approximated by the sum of the partial level densities corresponding to n quasiparticles excitation. The most probable values of the collective enhancement factor of the level density are found together with the thresholds of the next Cooper nucleons pair breaking. These data allow one to calculate the level density of practically any nucleus in given spin window in the framework of model concepts, taking into account all known nuclear excitation types. The presence of an approximation results discrepancy with theoretical statements specifies the necessity of rather essentially developing the level density models. It also indicates the possibilities to obtain the essentially new information on nucleon correlation functions of the excited nucleus from the experiment.Comment: 29 pages, 8 figures, 2 table

The Impact of QE on Liquidity: Evidence from the UK Corporate Bond Purchase Scheme

In August 2016, the Bank of England (BoE) announced a Corporate Bond Purchase Scheme (CBPS) to purchase up to $10bn of sterling corporate bonds. To investigate the impact of these purchases on liquidity, we create a novel dataset that combines transaction-level data from the secondary corporate bond market with proprietary offer-level data from the BoE's CBPS auctions. Identifying the impact of central bank asset purchases on liquidity is potentially impacted by reverse causality, because liquidity considerations might impact purchases. But the offer-level data allow us to construct proxy measures for the BoE's demand for bonds and auction participants' supply of bonds, meaning that we can control for the impact of liquidity on purchases. Across a range of liquidity measures, we find that CBPS purchases improved the liquidity of purchased bonds

Sudesna mjerenja γγ-raspada stanja 166Ho nastalih reakcijom (n,γ)

Levels of 166Ho were studied using thermal and average resonance neutron capture and with the (d,p) and (d,3He) reactions. We have devoted a large effort to the measurements of the γγ-coincidence spectra in the broad energy region 50 - 6243 keV. Based on these data and those of earlier studies, the levels are grouped into 23 rotational bands. Among them are 6 new ones. The results are in good agreement with the semiempirical and quasiparticle-phonon model, where Coriolis and residual interactions are taken into account. Details of model interpretation have been presented in a previously published paper.Proučavali smo stanja 166Ho nastala termičkim i prosječnim rezonantnim uhvatom neutrona, te (d,p) i (d,3He) reakcijama. Uložili smo velik trud u mjerenjima sudesnih γγ-spektara u širokom energijskom području od 50 do 6243 keV. Na osnovi tih i ranijih podataka, stanja su grupirana u 23 rotacijske vrpce. Među njima je i 6 novih. Ishodi su u suglasju s poluempiričkim i kvazičestično-fononskim modelom, uzimajući u obzir Coriolisovo međudjelovanje i rezidualne interakcije. Podrobnosti modelskog tumačenja objavljene u u ranijem članku

Sudesna mjerenja γγ-raspada stanja 166Ho nastalih reakcijom (n,γ)

Levels of 166Ho were studied using thermal and average resonance neutron capture and with the (d,p) and (d,3He) reactions. We have devoted a large effort to the measurements of the γγ-coincidence spectra in the broad energy region 50 - 6243 keV. Based on these data and those of earlier studies, the levels are grouped into 23 rotational bands. Among them are 6 new ones. The results are in good agreement with the semiempirical and quasiparticle-phonon model, where Coriolis and residual interactions are taken into account. Details of model interpretation have been presented in a previously published paper.Proučavali smo stanja 166Ho nastala termičkim i prosječnim rezonantnim uhvatom neutrona, te (d,p) i (d,3He) reakcijama. Uložili smo velik trud u mjerenjima sudesnih γγ-spektara u širokom energijskom području od 50 do 6243 keV. Na osnovi tih i ranijih podataka, stanja su grupirana u 23 rotacijske vrpce. Među njima je i 6 novih. Ishodi su u suglasju s poluempiričkim i kvazičestično-fononskim modelom, uzimajući u obzir Coriolisovo međudjelovanje i rezidualne interakcije. Podrobnosti modelskog tumačenja objavljene u u ranijem članku

Insights into globalization: comparison of patient characteristics and disease progression among geographic regions in a multinational Alzheimer’s disease clinical program

Background: Globalization of clinical trials has important consequences for trial planning and interpretation. This study investigated heterogeneity in patient characteristics and outcomes among world regions in the global idalopirdine Phase 3 clinical program. Methods: Data were pooled from three 24-week randomized controlled trials in patients aged ≥ 50 years with mild-to-moderate Alzheimer’s disease (AD) (n = 2506). Patients received idalopirdine (10, 30, or 60 mg/day) or placebo, added to cholinesterase inhibitor treatment. Patients were categorized into the following regions: Eastern Europe/Turkey (n = 759), Western Europe/Israel (n = 709), USA/Canada (n = 444), South America/Mexico (n = 361), Asia (n = 134), and Australia/South Africa (n = 99). For each region, operational characteristics, baseline demographic and clinical characteristics, adverse events, and mean change from baseline to week 24 in clinical rating scale scores (placebo group only) were summarized using descriptive statistics. Results: Completion rates were 0.86–0.90 in all regions. Heterogeneity among global regions was evident. Protocol deviations were twice as common in South America/Mexico as in USA/Canada (2.64 vs 1.35 per patient screened). Educational level ranged from 9.2 years in South America/Mexico to 13.4 years in USA/Canada. APOE ε4 carriage was 80.6% in Australia/South Africa, 63.1% in Western Europe/Israel, and &lt; 60% in other regions. Screening Mini-Mental State Examination scores were higher in Eastern Europe/Turkey (18.0) and USA/Canada (17.5) than in other regions (16.9–17.1). Baseline AD Assessment Scale-Cognitive subscale (ADAS-Cog) scores ranged from 24.3 in USA/Canada to 27.2 in South America/Mexico. Baseline AD Cooperative Study - Activities of Daily Living, 23-item version (ADCS-ADL23) scores ranged from 58.5 in USA/Canada to 53.5 in Eastern Europe/Turkey. In the placebo group, adverse events were 1.6–1.7 times more common in Western Europe/Israel, USA/Canada, and Australia/South Africa than in Eastern Europe/Turkey. On the ADAS-Cog, Australia/South Africa and Western Europe/Israel showed the most worsening among patients receiving placebo (1.56 and 1.40 points, respectively), whereas South America/Mexico showed an improvement (−0.71 points). All regions worsened on the ADCS-ADL23, from −3.21 points in Western Europe/Israel to −0.59 points in Eastern Europe/Turkey. Conclusions: Regional heterogeneity - in terms of study conduct, patient characteristics, and outcomes-exists, and should be accounted for, when planning and conducting multinational AD clinical trials. Trial registration ClinicalTrials.gov, NCT01955161. Registered on 27 September 2013. ClinicalTrials.gov, NCT02006641. Registered on 5 December 2013. ClinicalTrials.gov, NCT02006654. Registered on 5 December 2013

Complementary and alternative medical therapy utilization by people with chronic fatiguing illnesses in the United States

<p>Abstract</p> <p>Background</p> <p>Chronic fatiguing illnesses, including chronic fatigue syndrome (CFS), pose a diagnostic and therapeutic challenge. Previous clinical reports addressed the utilization of health care provided to patients with CFS by a variety of practitioners with other than allopathic training, but did not examine the spectrum of complementary and alternative medicine (CAM) therapies used. This study was designed to measure CAM therapy use by persons with fatiguing illnesses in the United States population.</p> <p>Methods</p> <p>During a random-digit dialing survey to estimate the prevalence of CFS-like illness in urban and rural populations from different geographic regions of the United States, we queried the utilization of CAM including manipulation or body-based therapies, alternative medical systems, mind-body, biologically-based, and energy modalities.</p> <p>Results</p> <p>Four hundred forty fatigued and 444 non-fatigued persons from 2,728 households completed screening. Fatigued subjects included 53 persons with prolonged fatigue, 338 with chronic fatigue, and 49 with CFS-like illness. Mind-body therapy (primarily personal prayer and prayer by others) was the most frequently used CAM across all groups. Among women, there was a significant trend of increasing overall CAM use across all subgroups (p-trend = 0.003). All categories of CAM use were associated with significantly poorer physical health scores, and all but one (alternative medicine systems) were associated with significantly poorer mental health scores. People with CFS-like illness were significantly more likely to use body-based therapy (chiropractic and massage) than non-fatigued participants (OR = 2.52, CI = 1.32, 4.82). Use of body-based therapies increased significantly in a linear trend across subgroups of non-fatigued, prolonged fatigued, chronic fatigued, and CFS-like subjects (p-trend = 0.002). People with chronic fatigue were also significantly more likely to use body-based therapy (OR = 1.52, CI = 1.07, 2.16) and mind-body (excluding prayer) therapy than non-fatigued participants (OR = 1.73, CI = 1.20 – 2.48).</p> <p>Conclusion</p> <p>Utilization of CAM was common in fatiguing illnesses, and was largely accounted for by the presence of underlying conditions and poor physical and mental health. Compared to non-fatigued persons, those with CFS-like illness or chronic fatigue were most likely to use body-based and mind-body therapies. These observations have important implications for provider education programs and development of intervention strategies for CFS.</p

Prevalence of chronic fatigue syndrome in metropolitan, urban, and rural Georgia

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