The response of corporate investments in the US to oil price changes: the role of asymmetries

This paper investigates the influence of oil price changes on corporate investment in the US using a large sample of 15,411 companies from 1984 to 2017. It adds to the literature by showing an asymmetric response of capital investments to oil price changes for non-oil companies. Particularly, positive oil price changes have a larger adverse impact on investments than the positive impact created by negative oil price changes. These results are important in assessing the impact of energy price fluctuations on the long-term investment decisions of US companies

Time-varying transmission between oil and equities in the MENA region: New evidence from DCC-MIDAS analyses

In this paper we use the DCC-MIDAS (Dynamic Conditional Correlation-Mixed Data Sampling) model to infer the association between oil and equities in five MENA countries between February 2006 and April 2017. The model indicates that higher oil returns tends to reduce the long-term risk of the Saudi market, but to increase it in other markets. The risk transfer from oil to MENA equities is found to be weak. The dynamic conditional correlation between oil and equities is not always positive and it unexpectedly changes sign during the sample period. However, the association always strengthens when there is a large draw down in oil prices as well as during periods of high volatility. Finally, we find that short term association occasionally breaks from the longer-term correlation particularly in Egypt and Turkey. These patterns of influence and associations are unique, and have important implications for equity portfolio managers who are interested in investing in energy and MENA equities

The connectedness and hedging between gold and Islamic securities in the short, medium and long term

This paper investigates the dynamic connectedness between gold, sukuk and Islamic equities at multiple investment horizons, it also computes optimal hedge ratios and portfolio weights for these assets. Our findings suggest that gold hedges the risk of sukuk in the short and medium terms. We find also that gold plays an average but stable role in hedging and diversifying Islamic equities across all investment horizons. Moreover, we find that gold–Islamic assets portfolio provided a better risk diversification in the short term. These empirical findings are important as they highlight the role of gold in diversifying and managing the risks of portfolios that invest in Islamic assets

The co-movement between oil and clean energy stocks: A wavelet-based analysis of horizon associations

The production of clean energy is crucial for protecting the environment and satisfying the future demand for energy. However, the growth in clean energy production and consumption is influenced by the developments in the oil and the clean energy technology markets. Thus, it is crucial to study the association among these markets and this is the main objective of this research. Compared to the existing literature, we provide evidence from multiple time horizons. In particular, we combine wavelets over various time scales with multivariate GARCH (MGARCH) to find significant bidirectional return and risk transfer from oil and technology to the clean energy market. The transmissions are found to be more pronounced at longer time horizons. These results highlight the importance of certainty and stability in the oil and technology markets for the growth of clean energy particularly in the long term

Oil price changes and industrial output in the MENA region: nonlinearities and asymmetries

In this paper, we investigate the nature of asymmetry in the influence of oil price changes on output in six MENA countries. To get more observations for our analysis, we proxy GDP with industrial output and hence our inference is based on a relatively larger sample compared to previous studies. The results that we obtain are interesting and intuitive. First, we find that growth in MENA countries is linked to oil in the sense that it benefits from higher oil prices and it gets hurt by a fall in the oil market. Moreover, there are pronounced short- and long-term asymmetries in the influence of oil on output. In particular, the output is faster to respond to increases in the oil price than it responds to decreases. The long-term influence to a rise in oil is also higher, though it is realized over a longer period. These results are important and can be used to guide policies that are concerned with stabilizing the economies of the MENA region against oil price fluctuations

The effects of investor emotions sentiments on crude oil returns: A time and frequency dynamics analysis

In this paper, we use wavelet coherence analysis to find that sentiment has a significant effect on crude oil returns that lasts over various investment horizons. While oil returns are positively associated with the sentiments of optimism and trust, it is negatively linked to fear and anger. These relations are more pronounced over the medium and the long term. Additionally, we find that short-term oil returns are relatively more sentiment-sensitive during turbulent periods than in normal conditions. These results highlight the importance of sentiment and investor psychology in the crude oil market

OPEC meetings, oil market volatility and herding behaviour in the Saudi Arabia stock market

We investigate the influence of oil market volatility and hand‐picked OPEC meetings data on herding tendency in the Saudi equity market. Our results show the presence of significant herding behaviour in the Saudi market; surprisingly this herding behaviour is independent of oil market volatility. Importantly, we find herding on and around the OPEC meeting days however this is only limited to a period of high global uncertainty that is, during the Global Financial Crisis period (GFC) of 2008–2010. However, when we filter out factor‐based herding in the Saudi equities, we also find persistent herding in the post GFC period. These results are consistent when we assess the impact of OPEC meetings using event windows of one to 5 days before and after the announcement. In consideration of the crucial role of OPEC in determining the oil prices, we explain our results of Saudi market herding on and around OPEC meeting days for the prior announcement ambiguity and corrections before, on and after the announcements on global supply. Our results show that this tendency has originated during the GFC, has persisted in the post‐GFC in the Saudi equities and surprisingly, is largely found absent in the periods when the Saudi equity market witnessed bullish market conditions. Our results are robust after accounting for common factor return variations in equity returns, the unconditional and conditional estimates of the volatility in oil prices and several event windows around OPEC meeting days

Prevalence and sociodemographic correlates of stunting, underweight, and overweight among Palestinian school adolescents (13-15 years) in two major governorates in the West Bank

<p>Abstract</p> <p>Background</p> <p>There is little information about height and weight status of Palestinian adolescents. The objective of this paper was to assess the prevalence of stunting, underweight, and overweight/obesity among Palestinian school adolescents (13-15 years) and associated sociodemographic factors in 2 major governorates in the West Bank.</p> <p>Methods</p> <p>A Cross-sectional survey was conducted in 2005 comprising 1942 students in 65 schools in Ramallah and Hebron governorates. Data was collected through self-administered questionnaires from students and parents. Weights and heights were measured. Overweight and obesity were assessed using the 2000 Centers for Disease Control and Prevention (CDC) reference and the International Obesity Task Force (IOTF) criteria. Stunting and underweight were assessed using the 2000 CDC reference.</p> <p>Results</p> <p>Overweight/obesity was more prevalent in Ramallah than in Hebron and affected more girls than boys. Using the 2000 CDC reference, the prevalence of overweight and obesity in Ramallah among boys was 9.6% and 8.2%, respectively versus 15.6% and 6.0% among girls (P < 0.01). In Hebron, the corresponding figures were 8.5% and 4.9% for boys and 13.5% and 3.4% for girls (P < 0.01). Using the IOTF criteria, the prevalence of overweight and obesity among boys in Ramallah was 13.3% and 5.2%, respectively versus 18.9% and 3.3% for girls. The prevalence of overweight and obesity among boys in Hebron was 10.9% and 2.2%, respectively versus 14.9% and 2.0% for girls. Overweight/obesity was associated with high standard of living (STL) among boys and with the onset of puberty among girls. More boys were underweight than girls, and the prevalence was higher in Hebron (12.9% and 6.0% in boys and girls, respectively (P < 0.01)) than in Ramallah (9.7% and 3.1% in boys and girls, respectively (p < 0.01)). The prevalence of stunting was similar in both governorates, and was higher among boys (9.2% and 9.4% in Ramallah and Hebron, respectively) than among girls (5.9% and 4.2% in Ramallah and Hebron, respectively). Stunting was negatively associated with father's education among boys and with urban residence, medium STL and onset of puberty among girls.</p> <p>Conclusion</p> <p>Under- and overnutrition co-exist among Palestinian adolescents, with differences between sexes. Region, residence, STL, and onset of puberty were associated factors.</p

Infertility treatment outcome in sub groups of obese population

<p>Abstract</p> <p>Background</p> <p>Obesity is a common disorder with a negative impact on IVF treatment outcome. It is not clear whether morbidly obese women (BMI >= 35 kg/m2) respond to treatment differently as compared to obese women (BMI = 30–34.9 kg/m2) in IVF. Our aim was to compare the outcome of IVF or ICSI treatments in obese patients to that in morbidly obese patients.</p> <p>Methods</p> <p>This retrospective cohort study was conducted in a tertiary care centre. Patients inclusion criteria were as follows; BMI ≥ 30, age 20–40 years old, first cycle IVF/ICSI treatment with primary infertility and long follicular pituitary down regulation protocol.</p> <p>Results</p> <p>A total of 406 obese patients (group A) and 141 morbidly obese patients (group B) satisfied the inclusion criteria. Average BMI was 32.1 ± 1.38 kg/m2 for group A versus 37.7 ± 2.99 kg/m²for group B. Patient age, cause of infertility, duration of stimulation, fertilization rate, and number of transferred embryos were similar in both groups. Compared to group A, group B had fewer medium size and mature follicles (14 vs. 16), fewer oocytes collected (7 vs. 9) and required higher doses of HMG (46.2 vs. 38.5 amps). There was also a higher cancellation rate in group B (28.3% vs. 19%) and lower clinical pregnancy rate per started cycle (19.9% vs. 28.6%).</p> <p>Conclusion</p> <p>In a homogenous infertile and obese patient population stratified according to their BMI, morbid obesity is associated with unfavorable IVF/ICSI cycle outcome as evidenced by lower pregnancy rates. It is recommended that morbidly obese patients undergo appropriate counseling before the initiation of this expensive and invasive therapy.</p

Can gold be used as a hedge against the risks of Sharia-compliant securities? Application for Islamic portfolio management

In this paper, we investigate whether gold hedges Sharia-compliant stocks and Sukuk during the period from September 2005 to October 2017. The inference is taken by using both the DCC-GARCH model and the wavelet coherence analysis. On the whole, our finding suggests that gold is not effective in hedging the fluctuations of Sharia-compliant securities. However, we find that combining gold with stocks (and Sukuk) is useful in diversification and portfolio optimization. These results imply that, while gold is an excellent hedge for plain vanilla securities, it is not for Islamic exposures. This is important in light of the increasing amount of assets that are managed according to Islamic screening