title: Trade, migration, poverty and inequality: A global perspective

authors: Abdul Ghani, Rosmaiza Binti

subjects: Bilateral trade

abstract: Trade and migration have been extensively studied in a variety of disciplines but their inter relationship is still arguable. It is crucial to understand how trade and migration are linked, since they are important elements in a modern, globalized economy. This thesis presents three interconnected studies on trade and migration that make use of newly estimated international migration flows data, to understand these relationships and the potential contributions of trade and migration to global poverty and inequality reduction. The first study examines the bi-directional relationship between trade and migration using international bilateral trade and migration flows data within a seemingly unrelated regression gravity model framework. The study finds that trade and migration are complements, which means that larger migration flows are associated with higher trade flows, and vice versa. Although these results do not definitively demonstrate causality, they suggest that, if world trade decreases due to countries implementation on current protectionist policies, migration flows might also be likely to decline. The second study extends the investigation by examining the causal relationship between trade and migration. The study uses a novel instrumental variables strategy, utilising World Trade Organisation (WTO) affiliation and average tariff rates as instruments within a gravity model framework, to overcome endogeneity in the regression model. The results suggest that trade is a causal driver of migration. This means that migration flows would increase following an increase in trade flows. The third study investigates whether international trade or migration has a larger effect on global extreme poverty and inequality. Again, an instrumental variables approach is used to address any endogeneity problems. The results suggest that trade has a larger potential impact on reducing extreme poverty and inequality. Overall, the outcomes of this thesis are important to policy makers in countries where growing migration is a political issue, and to origin countries that want to restrict the mobility of migrants and reduce the brain drain from their countries. It suggests that how countries treat their borders influences poverty and income inequality outcomes. This thesis suggests that trade provides a greater impact than migration on extreme poverty as well as inequality. Therefore, a country might want to allow freer trade by reducing their national border barriers, in order to reduce extreme poverty and inequality.

text: Trade, migration, poverty and inequality: A global perspective Trade and migration have been extensively studied in a variety of disciplines but their inter relationship is still arguable. It is crucial to understand how trade and migration are linked, since they are important elements in a modern, globalized economy. This thesis presents three interconnected studies on trade and migration that make use of newly estimated international migration flows data, to understand these relationships and the potential contributions of trade and migration to global poverty and inequality reduction. The first study examines the bi-directional relationship between trade and migration using international bilateral trade and migration flows data within a seemingly unrelated regression gravity model framework. The study finds that trade and migration are complements, which means that larger migration flows are associated with higher trade flows, and vice versa. Although these results do not definitively demonstrate causality, they suggest that, if world trade decreases due to countries implementation on current protectionist policies, migration flows might also be likely to decline. The second study extends the investigation by examining the causal relationship between trade and migration. The study uses a novel instrumental variables strategy, utilising World Trade Organisation (WTO) affiliation and average tariff rates as instruments within a gravity model framework, to overcome endogeneity in the regression model. The results suggest that trade is a causal driver of migration. This means that migration flows would increase following an increase in trade flows. The third study investigates whether international trade or migration has a larger effect on global extreme poverty and inequality. Again, an instrumental variables approach is used to address any endogeneity problems. The results suggest that trade has a larger potential impact on reducing extreme poverty and inequality. Overall, the outcomes of this thesis are important to policy makers in countries where growing migration is a political issue, and to origin countries that want to restrict the mobility of migrants and reduce the brain drain from their countries. It suggests that how countries treat their borders influences poverty and income inequality outcomes. This thesis suggests that trade provides a greater impact than migration on extreme poverty as well as inequality. Therefore, a country might want to allow freer trade by reducing their national border barriers, in order to reduce extreme poverty and inequality.

year: 2020

title: Aquatic ecology of Lake Rotokare, Taranaki, and options for restoration

authors: Hicks, Brendan J.

subjects: Lake Rotokare

abstract: Lake Rotokare is a 17.8-ha natural lake in eastern Taranaki, located 12 km east of Eltham in the 230-ha Rotokare Scenic Reserve. In 2008, the Rotokare Scenic Reserve Trust completed construction of an 8.2-km predator proof fence around the reserve.

Frequent algal blooms in summer have led to long periods of lake closure to boating and contact recreation. As there are few lakes in the Taranaki region, these closures are a nuisance to the local community. The objectives of this study were to quantitatively survey the fish community of the lake and to evaluate the lake water quality for the Rotokare Scenic Reserve Trust for the purpose of advising on options for lake restoration.

Water quality has not deteriorated since 1976-1980, and, if anything, has improved. Secchi disc depth in 2013 (1.95 m) was very similar to measurements in summer 1980 (mean 1.93 m on 30 January 1980). Mean dissolved reactive phosphorus (± 95% confidence interval) was greater in 1976 (190±50 mg/m³) than mean phosphate concentration in 2013 (93±31 mg/m³, p < 0.05, Kolmogorov-Smirnov two-sample test). The thermocline was deeper in 2013 at 6-7 m compared to 3-4 m in 1977. This indicates that a much greater volume of the lake was oxygenated in February 2013 than in February 1977. Also, the intensity of stratification was less in 2013, as the dissolved oxygen concentration below the thermocline was 21027% compared to just 3% in 1977. This suggests that an improvement in water quality has occurred, probably as a result of stock exclusion.

To sample the fish community, boat electrofishing was used at the total of six sites. The total length fished was 1,656 m, which was 6,624 m² in area. Eighty minutes of boat electrofishing caught 234 fish (217 perch, 16 shortfin eels, and 1 longfin eel). Fishing at night showed a 16-fold increase in the catch rate of perch (125 fish/10 min of fishing) compared to fishing during the day (8 fish/10 min of fishing).

Perch dominate the fish community in Lake Rotokare and the biomass and density of eels are low, which is unusual for Taranaki water bodies. The mean density of perch was 4.49 fish/100 m², and the mean density for eels was 0.29 fish/100 m². The lower eel density may be a result of impaired access for eels or may be the result of predation by perch on migrant juvenile eels. There have been changes in the zooplankton community since 1980. The North American invader Daphnia galeata was not found in 1980, and appears to have now replaced the cladoceran Bosmina meridionalis and copepod Boeckella sp. We also found a diverse rotifer community.

text: Aquatic ecology of Lake Rotokare, Taranaki, and options for restoration Lake Rotokare is a 17.8-ha natural lake in eastern Taranaki, located 12 km east of Eltham in the 230-ha Rotokare Scenic Reserve. In 2008, the Rotokare Scenic Reserve Trust completed construction of an 8.2-km predator proof fence around the reserve.

Frequent algal blooms in summer have led to long periods of lake closure to boating and contact recreation. As there are few lakes in the Taranaki region, these closures are a nuisance to the local community. The objectives of this study were to quantitatively survey the fish community of the lake and to evaluate the lake water quality for the Rotokare Scenic Reserve Trust for the purpose of advising on options for lake restoration.

Water quality has not deteriorated since 1976-1980, and, if anything, has improved. Secchi disc depth in 2013 (1.95 m) was very similar to measurements in summer 1980 (mean 1.93 m on 30 January 1980). Mean dissolved reactive phosphorus (± 95% confidence interval) was greater in 1976 (190±50 mg/m³) than mean phosphate concentration in 2013 (93±31 mg/m³, p < 0.05, Kolmogorov-Smirnov two-sample test). The thermocline was deeper in 2013 at 6-7 m compared to 3-4 m in 1977. This indicates that a much greater volume of the lake was oxygenated in February 2013 than in February 1977. Also, the intensity of stratification was less in 2013, as the dissolved oxygen concentration below the thermocline was 21027% compared to just 3% in 1977. This suggests that an improvement in water quality has occurred, probably as a result of stock exclusion.

To sample the fish community, boat electrofishing was used at the total of six sites. The total length fished was 1,656 m, which was 6,624 m² in area. Eighty minutes of boat electrofishing caught 234 fish (217 perch, 16 shortfin eels, and 1 longfin eel). Fishing at night showed a 16-fold increase in the catch rate of perch (125 fish/10 min of fishing) compared to fishing during the day (8 fish/10 min of fishing).

Perch dominate the fish community in Lake Rotokare and the biomass and density of eels are low, which is unusual for Taranaki water bodies. The mean density of perch was 4.49 fish/100 m², and the mean density for eels was 0.29 fish/100 m². The lower eel density may be a result of impaired access for eels or may be the result of predation by perch on migrant juvenile eels. There have been changes in the zooplankton community since 1980. The North American invader Daphnia galeata was not found in 1980, and appears to have now replaced the cladoceran Bosmina meridionalis and copepod Boeckella sp. We also found a diverse rotifer community.

year: 2013

title: Research note: Empirical analysis of ethnic pay gaps in New Zealand

authors: Cochrane, William

abstract: This research note explores the factors contributing to ethnic pay gaps in New Zealand. The emphasis here is on description, as a causal analysis is beyond the capability of the methods used. The gaps between the average (as well as median) hourly wages for the European workforce relative to Māori and Pacific workers are substantial. A statistical analysis by Treasury in 2018 also showed that the ratio in average hourly wages (based on published survey estimates by Stats NZ) for both ethnic groups relative to European had stayed at a similar level for the last decade; as they state “there has been movement from year to year but no consistent upward or downward trend” (Treasury, 2018, p.1).

text: Research note: Empirical analysis of ethnic pay gaps in New Zealand This research note explores the factors contributing to ethnic pay gaps in New Zealand. The emphasis here is on description, as a causal analysis is beyond the capability of the methods used. The gaps between the average (as well as median) hourly wages for the European workforce relative to Māori and Pacific workers are substantial. A statistical analysis by Treasury in 2018 also showed that the ratio in average hourly wages (based on published survey estimates by Stats NZ) for both ethnic groups relative to European had stayed at a similar level for the last decade; as they state “there has been movement from year to year but no consistent upward or downward trend” (Treasury, 2018, p.1).

year: 2023-10-19