Determinants of trade union membership in Great Britain during 1991-2003

We analyse the determinants of union membership in the UK using data from the BHPS (1991-2003). Employing three alternative methodologies to control for the problem of initial conditions we find that union membership remains persistent even after controlling for the unobserved effect. There is evidence of a considerable correlation between the unobserved individual heterogeneity and the initial membership status. Ignoring this overstates the degree of state dependence of union membership greatly. The extent of state dependence in union membership status is notably higher in the (1991-1996) period estimates and appears to be more pronounced in the case of male employees for the entire period under analysis. The second period estimates reveal that unobserved heterogeneity has a more prominent impact in determining future unionisation probability versus past union membership. Finally, the estimates suggest that an individual´s propensity to unionise is determined by a mixture of industrial and personal characteristics. This is at odds with earlier studies, such as Booth (1986) and Wright (1995), failing to control for unobservable effects and concluding that personal attributes do not have a significant impact on unionisation propensity

Estimating union wage effects in Great Britain during 1991-2003

Using a dynamic model of unionism and wage determination we find that the unobserved factors that influence union membership also affect wages. The estimates suggest that UK trade unions still play a non-negligible, albeit diminishing, role in wage formation. It appears that the greater impact of un observables in determining individual union propensity concerning the second period under analysis, versus past unionisation experience, implies that those remaining in unions during (1997-2002) gain most from their sorting decision. The significant contribution of unobserved heterogeneity renders the total union wage differential highly variable across individuals. The endogeneity correction procedure employed yields a discernible pattern of the estimated union wage effect relative to OLS and Fixed effects. This is in line with Robinson (1989a) and Vella and Verbeek (1998) and refutes the pessimistic conclusions reached by Freeman and Medoff (1982) and Lewis (1986) that endogeneity correction methodologies do not contribute to our understanding of the union wage effect puzzle

Determinants of Trade Union Membership in Great Britain During 1991-2003

The determinants of union membership in the UK are analysed using the BHPS(1991-2003). The paper employs three alternative methodologies to control for the problem of initial conditions. Trade union membership is found to be persistent even after controlling for the unobserved effect. There is evidence of a considerable correlation between the unobserved individual heterogeneity and the initial condition. Ignoring this overstates the degree of state dependence of union membership greatly. The extent of state dependence in union membership status is notably higher in the (1991-1996) period estimates and appears to be more pronounced in the case of male employees for the entire period under consideration. Concerning the observed heterogeneity the estimates suggest that an individual's propensity to unionise is determined by a mixture of industrial and personal characteristics that have a differential impact on male and female propensities.Union membership, initial conditions, unobserved individual heterogeneity, state dependence, dynamic random effects probit models

Estimating Union Wage Effects in Great Britain During 1991-2003

Using a dynamic model of unionism and wage determination we find that the unobserved factors that influence union membership also affect wages. The estimates suggest that UK trade unions still play a non-negligible, albeit diminishing, role in wage formation. It appears that the greater impact of unobservables in determining individual union propensity concerning the second period under analysis, versus past unionisation experience, implies that those remaining in unions during (1997-2002) gain most from their sorting decision. The significant contribution of unobserved heterogeneity renders the total union wage differential highly variable across individuals. The endogeneity correction procedure employed yields a discernible pattern of the estimated union wage effect relative to OLS and Fixed effects. This is in line with Robinson (1989a) and Vella and Verbeek (1998) and refutes the pessimistic conclusions reached by Freeman and Medoff (1982) and Lewis (1986) that endogeneity correction methodologies do not contribute to our understanding of the union wage effect puzzle.union status, union wage effects, unobserved heterogeneity, dynamic model of unionism and wage determination

A two-stage approach of manufacturing FeAl40 iron aluminides by self-propagating synthesis and pressureless sintering

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Powder Metallurgy on 11 June 2018, available online at https://doi.org/10.1080/00325899.2018.1478778. Under embargo until 11 June 2019.A two-stage sintering process was successfully used to sinter FeAl to densification levels of just above 95% at a temperature of 1300 ºC. In the first stage, mixed iron and aluminium powders were synthesised at 750°C via Self-Propagating High-temperature Synthesis (SHS) to form brittle and porous Fe2Al5. Then the pellets were crushed and milled to various sizes and mixed with iron powders in the nominal composition of FeAl40 and pressurelessly sintered at a higher temperature to obtain a higher densification by taking advantage of the less violent exothermic reaction of Fe2Al5 and Fe. The intermediate and end products in SHS and sintering were characterised by SEM/EDX and XRD. The porosity level of the final FeAl40 product was controlled by the heating rate and powder size, which was also strongly influenced by the temperature, holding time and the ratio of the two powders.Peer reviewedFinal Accepted Versio

Estimating union wage effects in Great Britain during 1991-2003

Using a dynamic model of unionism and wage determination we find that the unobserved factors that influence union membership also affect wages. The estimates suggest that UK trade unions still play a non-negligible, albeit diminishing, role in wage formation. It appears that the greater impact of un observables in determining individual union propensity concerning the second period under analysis, versus past unionisation experience, implies that those remaining in unions during (1997-2002) gain most from their sorting decision. The significant contribution of unobserved heterogeneity renders the total union wage differential highly variable across individuals. The endogeneity correction procedure employed yields a discernible pattern of the estimated union wage effect relative to OLS and Fixed effects. This is in line with Robinson (1989a) and Vella and Verbeek (1998) and refutes the pessimistic conclusions reached by Freeman and Medoff (1982) and Lewis (1986) that endogeneity correction methodologies do not contribute to our understanding of the union wage effect puzzle.Union status, Union wage effects, Unobserved heterogeneity, Dynamic model of unionism and wage determination

Estimating union wage effects and the probability of union membership in the U.K. during 1991-2003

Using a dynamic model of unionism and wage determination we find that the unobserved factors that influence union membership also affect wages. We observe a significant decline in trade union membership persistence during the period under analysis. We find that UK trade unions still play a nonnegligible, albeit diminishing, role in wage formation. While unions were unable to establish a wage premium for male members during the two periods considered, the female union wage effect stood at (19.4%, 17.6%) during (1991-1996, 1997-2002) respectively. The endogeneity correction procedure employed yields a discernible pattern of the union wage effect relative to OLS and fixed effects thus, refuting the pessimistic conclusions reached by Freeman and Medoff (1982) and Lewis (1986) that endogeneity correction methodologies do not contribute to our understanding of the union wage effect puzzle.Union membership persistence, Union wage effects, Unobserved heterogeneity, Dynamic model of unionism and wage determination

Determinants of trade union membership in Great Britain during 1991-2003

We analyse the determinants of union membership in the UK using data from the BHPS (1991-2003). Employing three alternative methodologies to control for the problem of initial conditions we find that union membership remains persistent even after controlling for the unobserved effect. There is evidence of a considerable correlation between the unobserved individual heterogeneity and the initial membership status. Ignoring this overstates the degree of state dependence of union membership greatly. The extent of state dependence in union membership status is notably higher in the (1991-1996) period estimates and appears to be more pronounced in the case of male employees for the entire period under analysis. The second period estimates reveal that unobserved heterogeneity has a more prominent impact in determining future unionisation probability versus past union membership. Finally, the estimates suggest that an individual´s propensity to unionise is determined by a mixture of industrial and personal characteristics. This is at odds with earlier studies, such as Booth (1986) and Wright (1995), failing to control for unobservable effects and concluding that personal attributes do not have a significant impact on unionisation propensity.Union membership, Initial conditions, Unobserved individual heterogeneity, State dependence, Dynamic random effects probit models

The optimal use of tris-2-ethylhexylamine to recover hydrochloric acid and metals from leach solutions and comparison with other extractants

This document is the Accepted Manuscript version of the following article: Uchenna Kesieme, Andreas Chrysanthou, Maurizio Catulli, and Chu Yong Cheng, ‘The optimal use of tris-2-ethylhexylamine to recover hydrochloric acid and metals from leach solutions and comparison with other extractants’, Journal of Environmental Chemical Engineering, Vol. 6 (2): 3177-3184, April 2018. Under embargo until 1 May 2019. The final, definitive version is available online via: https://doi.org/10.1016/j.jece.2018.05.001This paper describes the use of TEHA for HCl recovery from a leach solution generated by a hydrometallurgical plant. Four organic extractants were tested including TEHA, Alamine 336, Cyanex 923 and TBP. TEHA organic system performed best in terms of acid extraction, stripping and scrubbing efficiency. The successive extraction shows that more than 99% HCl was extracted after three stages of extraction. Scrubbing tests with different A/O ratios at different temperatures were conducted to identify the optimal conditions to separate HCl, Mn and Fe. After scrubbing the loaded organic solution at an A/O ratio of 1:4 and 22 °C, 94–100% of entrained metals were removed in a single contact with only 5.2% acid lost in the loaded scrub liquor. It was found that the phase disengagement time was in the range of 2– 4 min for both extraction and stripping, indicating reasonable fast phase separation. Based on these results from batch tests, it can be expected that after optimisation in a counter current circuit consisting of extraction, scrubbing, selective and bulk stripping, nearly all metals and HCl would be recovered and recycled.Peer reviewe

A review of acid recovery from acidic mining waste solutions using solvent extraction

This is the peer reviewed version of the following article: Uchenna Kesieme, Andreas Chrysanthou, Maurizio Catulli, and Chu Yong Cheng, ‘A review of acid recovery from acidic mining waste solutions using solvent extraction’, Journal of Chemical Technology and Biotechnology, (2018), which has been published in final form at https://doi.org/10.1002/jctb.5728. Under embargo until 1 July 2019. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The minerals industry is increasingly being forced by regulatory and cost pressures to reduce the amount of liquid acidic waste they produce. This requires a strong focus on waste reduction by recycling, regeneration and reuse. Four mineral acids were examined for recovery from waste acidic solutions including H 2SO 4, HNO 3, HCl, and H 3PO 4. The selection of the optimal extractant for acid recovery was based on extraction, stripping and scrubbing efficiencies. The extractants suitable for the recovery of H 2SO 4 and HCl are in the order of TEHA > Cyanex 923 > TBP > Alamine 336. TEHA has the highest degree of acid extraction and stripping compared with Cyanex 923 and almost 99% of the acid can be stripped. Alamine 336 can extract higher acid (for H 2SO 4 and HCl systems) than Cyanex 923 and TBP. However loaded acid for Alamine 336 system cannot be stripped using water at 60°C. For the recovery of nitric and phosphoric acids from acidic waste effluents, TBP was the best option. This work clearly demonstrates that extractant suitable for acid extraction may not be suitable for its recovery. However such extractant may be applied for the removal of acid from any waste acidic solution sacrificing the back extraction of the loaded acid. The effective implementation of options for acid recovery was examined to improve sustainability in the mineral industry.Peer reviewe