Broad Index Research Articles

Prevalence, Risk Factors, and Clinical Profiles of Hepatitis D Virus in Nigeria: A Systematic Review, 2009–2024

Background: The World Health Organization (WHO) recommends hepatitis D virus (HDV) screening among hepatitis B virus (HBV) infected individuals, with a focus on priority populations in resource-limited settings like Nigeria. HDV infection is a growing public health challenge, particularly among individuals with chronic hepatitis B virus (HBV) infection. HDV accelerates liver disease progression and significantly increases the risk of cirrhosis and hepatocellular carcinoma. Despite this, the epidemiology of HDV in Nigeria remains inadequately documented. This scoping review critically evaluates the prevalence, risk factors, and clinical outcomes of HDV co-infection among HBV patients in Nigeria. Method: We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The review included observational cross-sectional studies published between 2009 and 2024. We focused on studies that used Immunoglobulin G (IgG) antibody testing or RNA-based diagnostics to assess HDV prevalence. We included PubMed, Google Scholar, and Dimensions databases due to their broad indexing and coverage of peer-reviewed articles and accessibility. We screened the studies for their relevance to HDV prevalence, risk factors, and clinical outcomes, while excluding those that only tested for IgM or HDV antigen. Eleven studies, with a combined sample size of 2308 participants, were included in the final analysis. We performed a narrative synthesis of the findings, considering geographic, gender, and age-based variations in HDV prevalence and clinical impact. Results: HDV prevalence among HBV-infected individuals in Nigeria ranged from 2.0% to 31.6%. The highest prevalence was reported in the Southwest (31.6%) among malaria patients, while lower rates were observed in the Southeast (2.8%). Prevalence was higher in males, particularly those aged 21–30 years in the Southwest and 31–40 years in other regions. RNA-based testing provided more accurate data on active viremia, with viremic HDV prevalence rates ranging from 3.2% to 16%. Triple infection with HIV/HBV/HDV was associated with significantly lower CD4+ cell counts and worse clinical outcomes, including elevated liver enzymes and rapid progression to liver cancer. Key risk factors for HDV co-infection included multiple sexual partners, sharing of needles, and unsafe medical practices. Co-infected patients demonstrated worse clinical outcomes, such as elevated liver enzymes, decompensated cirrhosis, and higher rates of hepatocellular carcinoma. Conclusions: Our review underscores the urgent need for routine HDV screening among HBV patients in Nigeria, especially given the severe clinical consequences of co-infection. The recent WHO guidelines recommending HDV screening align with our findings, which emphasize the importance of RNA-based HDV testing among HBV-positive patients to improve diagnostic accuracy. Public health efforts should prioritize tailored interventions based on geographic, age, and gender disparities in HDV prevalence. Triple infection with HIV/HBV/HDV requires integrated care models to address both immune suppressions as indicated by diminished CD4 cell count and liver disease progression, as these patients face worse outcomes. Targeted HDV screening in mostly affected demographics and geographies and improved Nigeria capacity for cheaper HDV RNA/PCR diagnostics can reduce liver-related morbidity and mortality caused by HBV, which can be worsened and accelerated by HDV coinfection.

The Impact of Crude Oil Price Shock: Evidence from Bangladesh

This study aims to estimate the impact of crude oil price on the DSEX broad index of the Dhaka stock exchange using the Vector Error Correction Model (VECM) for the study period 2013:01-2022:12. It has decomposed the oil price shock into supply side and demand side oil shock. The empirical result shows that the stock price decreases significantly with crude oil prices driven by the shock in oil production. In contrast, the improvement in global economic activity results in a shock in the oil price which has a significant positive impact on the stock price. Furthermore, the accumulated shock in oil prices has a significant positive impact on stock prices. The variance decomposition under the VEC model shows that the demand shock of oil price contributes more to the variation in stock price for the oil-importing country Bangladesh. Since different oil price shocks have different impacts, the policy maker and investors implement decisions based on the understating of the sources of the shocks.

Evaluating the Effectiveness of Macroeconomic Determinants on the Performance of the Dhaka Stock Exchange: A Time Series Approach

The present study examines the causal relationships between selected macroeconomic factors and the Dhaka Stock Exchange Broad Index (DSEX) performance from January 2014 to December 2023. Time series econometric techniques include Dickey-Fuller (ADF) and Phillips-Perron (PP) tests to verify stationarity, Granger causality to investigate short-term dynamics, and Johansen's co-integration test to evaluate long-term relationships. The results show that while there is no long-term cointegration, there are significant short-term relationships between macroeconomic variables and the DSEX broad index. GDP growth and unemployment significantly impact stock performance, with two-way causality. While interest rates and the money supply have little impact on the index, inflation forecasts trends in inflation even if it doesn't directly influence it. Overall, the DSEX broad index shows how important it is to Bangladesh's macroeconomic dynamics by accurately predicting changes in GDP growth, unemployment, and inflation. The researcher provides unique insights into the mechanics of the Bangladeshi stock market, filling a vacuum in the literature on emerging countries. It analyzes how macroeconomic conditions affect the DSEX index over time, including the COVID-19 pandemic. The study investigates the influence of several macroeconomic variables on DSEX Index performance, providing significant information for Bangladeshi investors and policymakers looking to increase profits, inform policy choices, and promote economic stability. To have a better knowledge of stock market dynamics, future studies should include other macroeconomic aspects and regional markets.

Parsing the Performance of Stock Market Indices Amidst COVID-19 and Russia-Ukraine War: A Comparative Study of DSEX, Nifty-50, and KSE-100

The primary objective of this investigation is to assess the performance of the benchmark indices in the stock markets of Bangladesh, India, and Pakistan, denoted by DSEX (Dhaka Stock Exchange Broad Index), Nifty-50 (National Stock Exchange Fifty), and KSE-100 (Karachi Stock Exchange 100 Index), respectively. Data is meticulously gathered across distinct periods, namely the pre-COVID, the COVID-19, and the concurrent COVID-19 era along with the Russia-Ukraine War period, and amid the consequent global ongoing financial crises. The study encompasses information spanning from July 2, 2013 to May 9, 2023, employing descriptive statistics, where both mean returns and risk-adjusted returns were calculated consecutively. The evaluation of diversification among the indices during the specified periods is conducted through descriptive statistics and Ordinary Least Squares (OLS) estimation. The findings of this study indicate that all the indices exhibited negative mean returns during the COVID-19 phase. Furthermore, both mean returns and risk-adjusted returns of the indices witnessed substantial increments amid the inflationary environment concurrent with the COVID-19 and Russia-Ukraine War periods. OLS estimation results suggest an absence of a discernible diversification relationship among the indices. In summary, our results underscore the dynamic nature of index prices across diverse temporal and global crisis scenarios. These implications offer valuable insights for investors and stockholders, enabling them to discern hedging opportunities and identify diversifiable indices within the global stock markets across disparate periods and crises.

Identification and forecasting of bull and bear markets using multivariate returns

SummaryBull and bear market identification generally focuses on a broad index of returns through a univariate analysis. This paper proposes a new approach to identify and forecast bull and bear markets through multivariate returns. The model assumes that all assets are directed by a common discrete state variable from a hierarchical Markov switching model. The hierarchical specification allows the cross‐section of state‐specific means and variances to differ over bull and bear markets. We investigate several empirically realistic specifications that permit feasible estimation even with 100 assets. Our results show that the multivariate framework provides competitive bull and bear regime identification and improves portfolio performance and density prediction compared with several benchmark models including univariate Markov switching models.

The Index of Parental Activities, Context and Experiences (I-PACE): Psychometric Properties of a New Brief Early Parenting Questionnaire

Time pressures make brevity important for parent self-report measures, yet evidence highlights the multi-faceted nature of parenting and contextual influences. To straddle these competing goals, we developed a brief (23-item) yet broad Index of Parental Activities, Context, and Experiences (I-PACE) aimed at parents of toddlers and pre-schoolers. In two studies we assessed the validity and reliability of the I-PACE. Study 1 involved 870 caregivers (95% female, 75% with degrees, 90% White British) and examined I-PACE ratings alongside; (a) ratings of children’s social-emotional skills and behavior problems; and (b) child age and parental depressive symptoms, to assess its sensitivity to contrasts in child development and parental experience. Study 2 included 191 families with 14-month-olds, for whom 188 mothers and 178 fathers completed the I-PACE and an index of life satisfaction. Supporting the replicability of findings from the I-PACE, both studies showed the same differentiated 5-factor structure (i.e., parental experiences, parenting activities, home environment quality, neighborhood environment quality and childcare environment quality). Supporting the I-PACE’s validity, Study 1 showed that all 5 factors were independently related to both children’s social-emotional skills and behavior problems, with predicted associations with child age and parental depressive symptoms. Supporting the I-PACE’s inter-rater reliability, within-couple associations were significant for parenting activities, home environment, neighborhood quality and childcare quality. Together, these findings indicate that the I-PACE offers a broad yet brief index of early parenting with good psychometric properties and we discuss promising avenues for future research.

The resource curse and the role of institutions revisited

AbstractMany studies have shown that natural resource abundant countries with strong institutions tend to escape the resource curse. Institutional quality has been examined using broad indices of rule of law, the rate of murder, the share of the shadow economy and provision of public goods. Nonetheless, we need to locate the specific institutional conditions under which the curse manifests since some “rule of law” countries like Nigeria and Angola are generally classified as resource cursed. In this review, I argue that managing and distributing natural resource wealth through a centralised planning strategy and lack of a binding long-term national development plan are institutional conditions that encourage government unaccountability as they do not restrict policy makers against discretionary distribution of natural resource windfall, rent seeking, clientelism and corruption which contribute to poor economic development and growth. Also, inadequate regulations on how to address the potential or actual impacts of natural resource extraction on the livelihood of local people and the environment tend to precipitate grievance-induced resource conflict.

CAPM and a new investment decision method

AbstractThe traditional CAPM explains the return on each security, while the current study suggests a new methodology for “picking” a broad index, based on regression trees. Analysts’ recommendations on market prices are analyzed, and a one to three‐stage method is employed. The analysis suggests a few rules of thumb (only one to three stages) for buying or selling the CRSP US market index. The findings are robust, and the rules are reliable. Researchers and practitioners may benefit greatly from the new rules.

Comparison of Markowitz Model and Index Model in Optimization of Portfolio

To compare the differences between Markowitz Model and the Single Index Model, we have used historical return data for ten stock which belong in groups to three different equity sectors to practically implement the Markowitz Model and the Single Index Model. We find the stocks in the same equity sector being noticeably positively correlated even after eliminating systemic risks, which violates the formal condition of the IM. Also, as a result of very detailed comparison, we can conclude that the IM serves as an accurate approximation of the MM in practical applications for large enough number of risky assets. And adding a broad index such as S&P 500 to an existing individual equities portfolio is improving its properties.

Modeling Price and Variance Jump Clustering Using the Marked Hawkes Process

Abstract We examine the clustering behavior of price and variance jumps using high-frequency data, modeled as a marked Hawkes process (MHP) embedded in a bivariate jump-diffusion model with intraday periodic effects. We find that the jumps of both individual stocks and a broad index exhibit self-exciting behavior. The three dimensions of the model, namely positive price jumps, negative price jumps, and variance jumps, impact one another in an asymmetric fashion. We estimate model parameters using Bayesian inference by Markov Chain Monte Carlo, and find that the inclusion of the jump parameters improves the fit of the model. When we quantify the jump intensity and study the characteristics of jump clusters, we find that in high-frequency settings, jump clustering can last between 2.5 and 6 hours on average. We also find that the MHP generally outperforms other models in terms of reproducing two cluster-related characteristics found in the actual data.

The BRICS in the sustainable agenda: Performance analysis of ESG indices in the financial markets in Brazil, China, India and South Africa

The term ESG emerged in the report of the Global Compact (UN) in partnership with the World Bank, entitled Who Cares Wins: Connecting Financial Markets to a Changing World. However, the concept and measurement associated with ESG is not a fixed concept and there is no consensus on the exact list of issues and their materiality, but it is certain that it affects the value creation of a company. In 2006, a grouping was created, incorporating the foreign policy of Brazil, Russia, India and China, the bloc focuses on solving socioeconomic problems and using its competitive advantages, the BRICS has a proposal for sustainable development and consequently ESG. This study is justified by the fact that several empirical evidences show the benefits of the ESG agenda in the market, however, there is a gap when considering developing countries. In this article, a comparison was made between returns and performances through the average return, then the risk measurement measures are presented, namely variance, standard deviation, volatility and value at risk, in addition to the calculation of covariance, correlation, beta and drawdown, with data from the MSCI ESG Leaders index. We confirm the theory of long-term gains since in the period studied the average profitability of the ESG indices were higher in all countries compared to the broad index. As for volatility risk measures, our study confirmed the hypothesis that the risks of larger companies are greater than those of ESG companies.

Restricted and repetitive behaviors and their developmental and demographic correlates in 4-8-year-old children: A transdiagnostic approach.

Background: Restricted and repetitive behaviors (RRBs) are a broad class of behaviors characterized by frequent action repetition and intense preference for sameness. Research has predominantly focused on RRBs in diagnosed clinical groups, particularly in autism spectrum disorder and genetic disorders. Using a transdiagnostic approach, the current study examined RRBs in a diverse sample of children in relation to developmental and demographic correlates (age, language, non-verbal ability, child anxiety, sex, and socioeconomic status). Separate analyses examined two RRB subtypes; repetitive sensory and motor behaviors (RSMB) and insistence on sameness (IS). Method: Children (N = 260, age 4-8 years, 174 male, 86 female) in mainstream schools identified by teachers as having behavioral, emotional, and/or cognitive difficulties, were assessed using the Repetitive Behavior Questionnaire-2 (RBQ-2), the British Picture Vocabulary Scale (BPVS), Lucid Ability Scale, the Welsh Index of Multiple Deprivation (WIMD) and the Screen for Child Anxiety Related Emotional Disorders (SCARED). Recruitment excluded diagnosed clinical conditions. The Strengths and Difficulties Questionnaire (SDQ) was used to assess children's difficulties. Results: RRB scores were of high frequency and the scores for the IS were higher than for RSMB. The severity of anxiety symptoms and male sex were significantly associated with both RRB subtypes, and younger age and SES scores were associated with IS. Elevated RRB total and subtype scores were significantly related to SDQ scores for emotion, conduct, hyperactivity, and peer-relations. Discussion: The study provides the first evidence of RRBs in a diverse sample of young children with emerging difficulties in behavior, cognition, and/or emotion. The results contribute to proposals about psychological development in RRB and indicate that RRBs are best represented on a continuum of severity found across children in the early school years. The results support previous findings of a relation between RRB and anxiety reported in clinical samples and importantly, they indicate that it is time to move beyond the study of categorically defined groups and consider correlates of RRBs that include broad indices of mental health and well-being.

A Polygenic Risk Score Enhances Risk Prediction for Adolescents' Antisocial Behavior over the Combined Effect of 22 Extra-familial, Familial, and Individual Risk Factors in the Context of the Family Check-Up.

Possessing informative tools to predict who is most at risk for antisocial behavior in adolescence is important to help identify families most in need of early intervention. Polygenic risk scores (PRSs) have been shown to predict antisocial behavior, but it remains unclear whether PRSs provide additional benefit above more conventional tools to early risk detection for antisocial behavior. This study examined the utility of a PRS in predicting adolescents' antisocial behavior after accounting for a broad index of children's contextual and individual risk factors for antisocial behavior. Participants were drawn from a longitudinal family-based prevention study (N = 463; Ncontrol = 224; 48.8% girls; 45.1% White; 30.2% Black; 12.7% Hispanic/Latino, 10.4% biracial; 0.2% Native American). Participants were recruited from US-based Women, Infants, and Children Nutritional Supplement programs. A risk tolerance PRS was created from a genome-wide association study. We created a robust measure capturing additive effects of 22 conventional measures of a risk of antisocial behavior assessed at child age 2 (before intervention). A latent variable capturing antisocial behavior (ages 10.5-16) was created. After accounting for intervention status and the conventional risk index, the risk tolerance PRS predicted independent variance in antisocial behavior. A PRS-by-conventional risk interaction showed that the conventional risk measure only predicted antisocial behavior at high levels of the PRS. Thus, the risk tolerance PRS provides unique predictive information above conventional screening tools and, when combined with them, identified a higher-risk subgroup of children. Integrating PRSs could facilitate risk identification and, ultimately, prevention screening, particularly in settings unable to serve all individuals in need.

ETF Basket-Adjusted Covariance estimation

The increase in trading frequency of Exchanged Traded Funds (ETFs) presents a positive externality for financial risk management when the price of the ETF is available at a higher frequency than the price of the component stocks. The positive spillover consists in improving the accuracy of pre-estimators of the integrated covariance of the stocks included in the ETF basket. The proposed ETF Basket-Adjusted Covariance (BAC) equals the pre-estimator plus a minimal adjustment matrix such that the covariance-implied stock-ETF covariation equals a target value. We focus on a truncated pre-averaged version of the (Hayashi and Yoshida, 2005) pre-estimator and derive the asymptotic properties of its implied stock-ETF covariation. The simulation study confirms that the accuracy gains are substantial in all cases considered. In the empirical part of the paper, we show the gains in tracking error efficiency when using the BAC adjustment to construct portfolios that replicate a broad index using a subset of stocks.

Skewness expectations and portfolio choice

Many models of investor behavior predict that investors prefer assets that they believe to have positively skewed return distributions. We elicit detailed return expectations for a broad index fund and a single stock in a representative sample of the Dutch population. The data show substantial heterogeneity in individuals’ skewness expectations of which only very little is captured by sociodemographics. Across assets, most respondents expect a higher variance and skewness for the individual stock compared to the index fund. Portfolio allocations increase with the skewness of respondents’ return expectations for the respective asset, controlling for other moments of a respondent’s expectations.

The Impact of COVID-19 in the Capital Market in Bangladesh

Background: COVID-19 has devastated the normal way of life. It has been raging over the globe since late January 2020. So far, 212 nations and territories throughout the world have been reported to be impacted. The viciousness of community transmission has reached its apex. Almost every country is waging a costly economic war against this epidemic. The situation of economic normality is becoming increasingly questionable as the epidemic spreads uncontrollably. Objective: In this study our main goal is to evaluate the impact of COVID-19 in the capital market in Bangladesh. Method: Data of each trading day’s last return is collected from the DSE and CSE web library. DSE and CSE All Share price Index is collected on daily and monthly basis from 2018 to 2021. Results: The capital market developments of the DSE and CSE from June 2020 to June 2021 shows that Both the Dhaka Stock Exchange (DSE) and the Chittagong Stock Exchange (CSE) showed an increased trend in terms of index and turnover at the end of June 2021 compared to the end of May 2021. The DSE broad index and the CSE all-share price index increased to 6150.48 points and 17795 points at the end of June 2021, respectively, from 5990.99 points and 17359.57 points at the end of May 2021. At the end of June 2021, the total turnover value of DSE and CSE traded shares were BDT 435.09 billion and BDT 21.3 billion, respectively, which was 40.30 percent and 37.72 percent higher than in May 2021. Whereas the ratio of market capitalization to GDP (at current market price) stood higher at 18.39 percent* at the end of June 2021which was 18.02 percent at the end of May 2021. Conclusion: COVID-19 has presented significant concerns to economic regularity and financial market stability. Nonetheless, it is anticipated that the gloomy days would pass quickly. We must be prepared to battle on if this worst-case situation lasts longer than planned. General investors must also do their role in maintaining our market image and .........

Causality among Stock Returns of Major South Asian Markets

The objective of this research is to investigate the existence of a causal connection between the daily stock returns of the key South Asian stock markets. To benefit from such integration, if there is any, investors and policymakers must craft and execute strategies that take this relationship into account. Researchers can also benefit from the findings since they will be able to craft research strategies based on this study while answering their respective research agendas. This paper considers daily returns of BSE Sensex 30, DSEX, and Karachi All Share indices as representatives of returns from stock markets of India, Bangladesh, and Pakistan respectively since these are the broad indices of their respective markets. Sri Lanka has been disqualified from the tests due to its recent economic fragility. Using 7,113 data points from the aforementioned markets between January 31, 2013, and August 31, 2022, Granger causality and augmented Dickey-Fuller test (ADF) has been applied to evaluate if these are stationary and exhibit any causal links. Results show that returns of all markets are stationary, disqualifying them from undergoing a co-integration test. Additionally, the Indian and Pakistani stock markets exhibit bidirectional causality, indicating that these markets' returns influence one another.

The Diversification of Portfolios under Different Conventional Scenarios in the Shock of COVID-19

Asset portfolio theory has traditionally been widely used in the financial field. Several studies have been made to demonstrate the superiority of this theory and many people have done many efforts to develop it. However, in the last two years, various industries have been hit by the COVID-19, and this paper is designed to investigate whether the asset portfolio still has a good risk diversification ability under different constraints in this context. In this paper, a portfolio is constructed using stocks of 10 companies from 5 industries and the SPX index, and the Markowitz Model and Index Model are used to calculate the returns and standard deviations of the portfolio under the four constraints. As a result, the limitation of short selling to stocks will increase the risk and reduce the profitability of the portfolio somehow but a well-diversified portfolio can reach the most requirements in the market, and the inclusion of the broad index into the portfolio has positive effect, which means a better diversification and higher profitability. Consequently, it can be concluded that the portfolio still has good risk diversification even under the shock of the COVID-19. This research could facilitate the study of portfolio theory under several different scenarios as well as contribute to investors’ better understanding of the risk diversification.

Disagreement in economic forecasts and equity returns: risk or mispricing?

PurposeThis paper investigates the role of economic disagreement in the cross-sectional pricing of individual stocks. Economic disagreement is quantified with ex ante measures of cross-sectional dispersion in economic forecasts from the Survey of Professional Forecasters (SPF), determining the degree of disagreement among professional forecasters over changes in economic fundamentals.Design/methodology/approachThe authors introduce a broad index of economic disagreement based on the innovations in the cross-sectional dispersion of economic forecasts for output, inflation and unemployment so that the index is a shock measure that captures different aspects of disagreement over economic fundamentals and also reflects unexpected news or surprise about the state of the aggregate economy. After building the broad index of economic disagreement, the authors test out-of-sample performance of the index in predicting the cross-sectional variation in future stock returns.FindingsUnivariate portfolio analyses indicate that decile portfolios that are long in stocks with the lowest disagreement beta and short in stocks with the highest disagreement beta yield a risk-adjusted annual return of 7.2%. The results remain robust after controlling for well-known pricing effects. The results are consistent with a preference-based explanation that ambiguity-averse investors demand extra compensation to hold stocks with high disagreement risk and the investors are willing to pay high prices for stocks with large hedging benefits. The results also support the mispricing hypothesis that the high disagreement beta provides an indirect way to measure dispersed opinion and overpricing.Originality/valueMost literature measures disagreement about individual stocks with the standard deviation of earnings forecasts made by financial analysts and examines the cross-sectional relation between this measure and individual stock returns. Unlike prior studies, the authors focus on disagreement about the economy instead of disagreement about earnings growth. The authors' argument is that disagreement about the economy is a major factor that would explain disagreement about stock fundamentals. The authors find that disagreement in economic forecasts does indeed have a significant impact on the cross-sectional pricing of individual stocks.

Understanding the inverse relationship between age and psychotic symptoms: The role of borderline personality traits.

There is a well-established inverse relationship between age and positive psychotic symptoms, both in patients with psychotic disorders and in general population samples with psychotic experiences. The reason for this inverse relationship is unclear. We hypothesized that life-course developmental changes in borderline personality traits, which also typically decline with age, might explain the inverse relationship between age and positive psychotic symptoms. We tested this hypothesis with data from 19,980 adults who completed 2000, 2007, and 2014 UK Adult Psychiatric Morbidity Survey studies. Hallucinations and delusions were assessed with the Psychosis Screening Questionnaire. Borderline features were assessed with the Structured Clinical Interview for DSM-IV Axis II Personality Disorders Screening Questionnaire. Logistic regression models with effect decompositions were used to conduct the analyses. As expected, age was negatively associated with hallucinations and delusions. These effects were wholly or mostly reduced after controlling for borderline features. Similar results were found in a subgroup of participants with a probable psychotic disorder. Repeating the analysis with a broad index of psychopathology severity instead of borderline features did not produce comparable results. Borderline factor scores reflecting identity/relationship disturbance, mood instability/anger, and self-harm/suicidality were created, all of which appeared to explain part of the inverse relationship between age and psychotic experiences. Declining borderline traits throughout adulthood may account for the reduced prevalence of positive psychotic symptoms in both clinical and non-clinical populations. Future research might evaluate the impact of treatments that target borderline traits on positive psychotic symptoms.