South Africa’s inflation persistence : a quantile regression framework

We study inflation persistence in South Africa using a quantile regression approach. We control for structural breaks using a quantile structural break test on a long span of inflation data. Our study includes persistence estimates for headline and core inflation - thus controlling for possible biases emanating from extremely volatile periods. South Africa's inflation persistence is lowest during the inflation targeting period regardless of the inflation measure. Inflation persistence is also constant over all quantiles during the inflation targeting regime for core inflation. There is a difference between the estimates from headline and core - headline persistence increases in relation to higher quantiles. Thus energy and food price shocks might de-stabilise inflation altogether.http://link.springer.com/journal/106442017-08-31hb2016Economic

Characterising the South Africa business cycle : is GDP difference-stationary or trend-stationary in a Markov-switching setup?

We test for a unit root in de-trended GDP in a two-state Markov switching specification using a modified Augmented Dickey-Fuller test. Our results show that a first difference GDP specification is preferred over the de-trended specification. In addition, the null of differencestationary GDP cannot be rejected. By implication, shocks to GDP are permanent which validates specifying trend GDP with a stochastic component – something that is inherently assumed in a number of research papers that estimate potential GDP growth and that model GDP in general equilibrium specifications.http://www.iei1946.it/en/rivista.phphttp://www.ge.camcom.gov.it/IT/Page/t01/view_html?idp=555am2017Economic

Allicin from garlic inhibits the biofilm formation and urease activity of Proteus mirabilis in vitro

Several virulence factors contribute to the pathogenesis of Proteus mirabilis. This study determined the inhibitory effects of allicin on urease, hemolysin and biofilm of P. mirabilis ATCC 12453 and its antimicrobial activity against 20 clinical isolates of P. mirabilis. Allicin did not inhibit hemolysin, whereas it did inhibit relative urease activity in both pre-lysed (half-maximum inhibitory concentration, IC50 = 4.15 μg) and intact cells (IC50 = 21 μg) in a concentration-dependent manner. Allicin at sub-minimum inhibitory concentrations (2-32 μg mL-1) showed no significant effects on the growth of the bacteria (P>0.05), but it reduced biofilm development in a concentration-dependent manner (P<0.001).A higher concentration of allicin was needed to inhibit the established biofilms. Using the microdilution technique, the MIC90 and MBC90 values of allicin against P. mirabilis isolates were determined to be 128 and 512 μg mL-1, respectively.The results suggest that allicin could have clinical applications in controlling P. mirabilis infections. © FEMS 2015. All rights reserved

Testing for bubbles in the BRICS stock markets

PURPOSE : The purpose of this paper is to investigate whether there exist multiple bubbles in the Brazil, Russia, India, China and South Africa (BRICS) stock markets. DESIGN/METHODOLOGY/APPROACH : In this study, the authors apply the generalized sup Augmented Dickey-Fuller test, a new recursive test proposed by Phillips et al. (2015) and use monthly data on stock price-dividend ratio. FINDINGS : The empirical results indicate that there exist multiple bubbles in the stock markets of the BRICS. Further, the dates of the bubbles also correspond to specific events in the stock markets of these economies. This finding has important economic and policy implications. ORIGINALITY/VALUE : The authors declare that this paper is original and has not been published by another journal previously.http://www.emeraldinsight.com/0144-3585.htmhttp://www.emeraldinsight.com/loi/jeshj2017Economic

The Feldstein–Horioka puzzle in South Africa : a fractional cointegration approach

The Feldstein–Horioka (FH) puzzle, that is the strong correlation between saving and investment in a world where obstacles to capital mobility are limited, has been studied extensively since it was exposed in 1980. Even though the theoretical and empirical literature has examined many of its potential causes, the puzzle persists. This paper aims at shedding further light on the issue by investigating the relationship between saving and investment in South Africa since 1946 using fractional integration and cointegration techniques to account for high persistence in the series. We find evidence of fractional cointegration between saving and investment, indicating some degree of persistence in the gap between the two variables.We also find a structural break in saving and investment ratios to GDP around 1980, which roughly coincides with the start of a financial deregulation process in South Africa. While fractional cointegration holds before the break, it does not thereafter. In other words, while the FH puzzle is observed before the start of financial deregulation, it subsequently disappears. This suggests that financial deregulation may have loosened the link between saving and investment.http://www.tandfonline.com/loi/rjte202017-09-30hb2016Economic

Impact assessment of pollarding on biometrical indices of Lebanon oak (Quercus libani Oliv.) in Belake Forests, Baneh

Pollarding of oak trees as a traditional practice has been done in northern Zagros forests and affects tree characteristics. In order to assess the effects of pollarding on biometrical indicesof Q. libani, a less-disturbed stand with an area of 0.65 ha and a pollarded stand with an area of 2.5 ha, with similar physiographic conditions were selected in Belakeh Forests, Baneh city of Kurdistan province of Iran. In each stand, diameter at breast height, collar diameter, total height, stem height, crown length and crown area of all Quercus libani trees over five cm dbh were measured. Ninteen sample trees in pollarded coppice stand and 26 sample trees in less-disturbed coppice stand were randomly selected to measure the diameter increment. Pairs of increment cores were extracted from each tree at the height of 50 cm using increment borer. Current annual increment in the samples was measured and the average annual increments in diameter classes were determined. Normality test was done, using the Kolmogorov–Smirnov test. Comparison of biometrical indiceswas done by Independent-samples T test. The results showed that the mean biometrical indices of Quercus libani were significantly different (P < 0.01) between the two stands. The value of the studied quantitative variables was greater in the less-disturbed stand. Furthermore, pollarding significantly increased the average diameter increment in pollarded oak trees (P < 0.01). The averages diameter increment and diameter increment percentage in pollarded stand were 3.41 mm and %2.83, respectively. Different values of the average diameter increment and the diameter increment percentage were obtained in the less-disturbed stand (2.23 mm and %1.02)

Odd log-logistic generalised Lindley distribution with properties and applications

In this paper, a new three-parameter lifetime model, called the odd log-logistic generalised Lindley distribution, is introduced. Some structural properties of the new distribution including ordinary and incomplete moments, quantile and generating functions and order statistics are obtained. The new density function can be expressed as a linear mixture of exponentiated Lindley densities. Different methods are discussed to estimate the model parameters and a simulation study is carried out to show the performance of the new distribution. The importance and flexibility of the new model are also illustrated empirically by means of two real data sets. Finally, Bayesian analysis and Gibbs sampling are performed based on the two real data sets

Testing the degree of persistence of Covid-19 using Fourier quantile unit root test

In this paper, we test the stochastic properties of daily accumulated number of confirmed cases of Covid-19 (ANCCC) in the 20 countries using Fourier quantile unit root test. The results indicate that the negative shocks to ANCCC series have long lasting effects in all countries (except China) and big positive shocks have permanent effects in some countries. Our results have important policy implications

[In Press] Tehran's house price ripple effects in Iran : application of bootstrap asymmetric panel granger non-causality in the frequency domain

The purpose of this study is to examine the ripple effects from Tehran, the capital city of Iran, to other major Iranian cities by applying a new methodological approach: a bootstrap asymmetric panel Granger non-causality in the frequency domain and a univariate stationary test with an unknown number and shape of break dates. To the best of our knowledge, this study is the first in the literature to combine two existing methods for testing ripple effect (Granger non-causality and price convergence hypothesis). Using semi-annual data from 1993 to 2017, our findings suggest that Tehran’s house price ripples out to the house prices of other cities, but it does not result in house price convergence toward Tehran. We also find that some cities are affected by only positive shocks of Tehran’s house price while some cities are affected by only negative shocks of Tehran’s house price; other cities are affected by both positive and negative shocks of Tehran’s house price