Can Health Human Capital Help the Sub-Saharan Africa Out of the Poverty Trap? An ARDL Model Approach.

This article explores the impact of health human capital on the poverty trap in Sub-Saharan Africa by autoregressive distribution lag model. In the long run, there is no evidence that health human capital can help the Sahara out of the poverty trap. While health human capital has a significant effect on poverty reduction in the short term. There is a threshold effect in the poverty reduction model of healthy human capital. When the economic development level reaches the threshold, the effect of poverty reduction is more obvious and deeper. The extended Solow economic growth model also proved that if the external human capital breaks through the threshold, it can make developing countries get rid of the poverty trap. Therefore, the economic development brought about by health care expenditure must benefit the poor in Sub-Saharan Africa and allow them to enjoy the welfare of social security.

Testing for multiple bubbles in the copper price: Periodically collapsing behavior.

This study investigates whether multiple bubbles exist in the copper price on the basis of the Generalized Supremum Augmented Dickey-Fuller (GSADF) approach (Phillips et al., 2013). This technique delivers date-stamping strategies for the emergence as well as collapse of explosive bubble episodes and is best suited for practical application to time series. The results reveal that four explosive bubbles are detected over the period of 1980-2019 when copper price deviates from fundamental value. Besides, this finding is in accordance with the asset pricing model (Gürkaynak, 2008), which generally considers both fundamental and bubble components in the presence of asset prices. Based on the empirical results, the multiple emergence and collapse of multiple price bubbles are attributed to speculation, depreciation of the U.S. dollar, an imbalance between supply and demand, and financial crises. Policymakers should actively recognize bubble episodes and monitor their evolution, which could be conducive to achieving the effective stabilization of the international copper price. To reduce excess price fluctuations and explosive copper bubbles, authorities should impose restrictions on excessive speculative behaviors under extreme market conditions.