title: PPP in OECD countries: An analysis of real exchange rate stationarity, cross-sectional dependency and structural breaks

authors: Holmes, Mark J.

subjects: heterogeneous dynamic panels

abstract: The stationarity of OECD real exchange rates over the period 1972-2008 is tested using a panel of 26 member countries. The methodology followed stems from the need to meet several key concerns: (i) the identification of which panel members are stationary; (ii) the presence of cross-sectional dependence among the countries in the panel; and (iii) the identification of potential structural breaks that might have occurred at different points in time. To address these concerns, we employ a recent test that examines the time series properties of the data within a panel framework, namely the Hadri and Rao (Oxford Bulletin of Economics and Statistics 70: 245-269, 2008) panel stationarity test. The real exchange rates of the 26 OECD countries are found to be stationary when considered as a panel, but only after allowing for endogenously-determined structural breaks and cross section dependence. We also find that once these structural breaks are removed from the underlying series, the half-life of shocks to the real exchange rate is much shorter than has been calculated in earlier studies.

text: PPP in OECD countries: An analysis of real exchange rate stationarity, cross-sectional dependency and structural breaks The stationarity of OECD real exchange rates over the period 1972-2008 is tested using a panel of 26 member countries. The methodology followed stems from the need to meet several key concerns: (i) the identification of which panel members are stationary; (ii) the presence of cross-sectional dependence among the countries in the panel; and (iii) the identification of potential structural breaks that might have occurred at different points in time. To address these concerns, we employ a recent test that examines the time series properties of the data within a panel framework, namely the Hadri and Rao (Oxford Bulletin of Economics and Statistics 70: 245-269, 2008) panel stationarity test. The real exchange rates of the 26 OECD countries are found to be stationary when considered as a panel, but only after allowing for endogenously-determined structural breaks and cross section dependence. We also find that once these structural breaks are removed from the underlying series, the half-life of shocks to the real exchange rate is much shorter than has been calculated in earlier studies.

year: 2012

title: How important is selection? Experimental vs. non-experimental measures of the income gains from migration

authors: McKenzie, David

subjects: New Zealand

abstract: How much do migrants stand to gain in income from moving across borders? Answering this question is complicated by non-random selection of migrants from the general population, which makes it hard to obtain an appropriate comparison group of non-migrants. New Zealand allows a quota of Tongans to immigrate each year with a random ballot used to choose among the excess number of applicants. A unique survey conducted by the authors allows experimental estimates of the income gains from migration to be obtained by comparing the incomes of migrants to those who applied to migrate, but whose names were not drawn in the ballot, after allowing for the effect of non-compliance among some of those whose names were drawn. We also conducted a survey of individuals who did not apply for the ballot. Comparing this non-applicant group to the migrants enables assessment of the degree to which non-experimental methods can provide an unbiased estimate of the income gains from migration. We find evidence of migrants being positively selected in terms of both observed and unobserved skills. As a result, non-experimental methods other than instrumental variables are found to overstate the gains from migration by 20–82%, with difference-in-differences and bias-adjusted matching estimators performing best among the alternatives to instrumental variables. (JEL: J61, F22, C21)

text: How important is selection? Experimental vs. non-experimental measures of the income gains from migration How much do migrants stand to gain in income from moving across borders? Answering this question is complicated by non-random selection of migrants from the general population, which makes it hard to obtain an appropriate comparison group of non-migrants. New Zealand allows a quota of Tongans to immigrate each year with a random ballot used to choose among the excess number of applicants. A unique survey conducted by the authors allows experimental estimates of the income gains from migration to be obtained by comparing the incomes of migrants to those who applied to migrate, but whose names were not drawn in the ballot, after allowing for the effect of non-compliance among some of those whose names were drawn. We also conducted a survey of individuals who did not apply for the ballot. Comparing this non-applicant group to the migrants enables assessment of the degree to which non-experimental methods can provide an unbiased estimate of the income gains from migration. We find evidence of migrants being positively selected in terms of both observed and unobserved skills. As a result, non-experimental methods other than instrumental variables are found to overstate the gains from migration by 20–82%, with difference-in-differences and bias-adjusted matching estimators performing best among the alternatives to instrumental variables. (JEL: J61, F22, C21)

year: 2010

title: Ethnic disparities in breast cancer survival in New Zealand: which factors contribute?

authors: Tin Tin, Sandar

subjects: Breast cancer

abstract: Background: New Zealand has major ethnic disparities in breast cancer survival with Maori (indigenous people) and Pacific women (immigrants or descended from immigrants from Pacific Islands) faring much worse than other ethnic groups. This paper identified underlying factors and assessed their relative contribution to this risk differential. 
Methods: This study involved all women who were diagnosed with primary invasive breast cancer in two health regions, covering about 40% of the national population, between January 2000 and June 2014. Maori and Pacific patients were compared with other ethnic groups in terms of demographics, mode of diagnosis, disease factors and treatment factors. Cox regression modelling was performed with stepwise adjustments, and hazards of excess mortality from breast cancer for Maori and Pacific patients were assessed. 
Results: Of the 13,657 patients who were included in this analysis, 1281 (9.4%) were Maori, and 897 (6.6%) were Pacific women. Compared to other ethnic groups, they were younger, more likely to reside in deprived neighbourhoods and to have co-morbidities, and less likely to be diagnosed through screening and with early stage cancer, to be treated in a private care facility, to receive timely cancer treatment, and to receive breast conserving surgery. They had a higher risk of excess mortality from breast cancer (age and year of diagnosis adjusted hazard ratio: 1.76; 95% CI: 1.51-2.04 for Maori and 1.97; 95% CI: 1.67-2.32 for Pacific women), of which 75% and 99% respectively were explained by baseline differences. The most important contributor was late stage at diagnosis. Other contributors included neighbourhood deprivation, mode of diagnosis, type of health care facility where primary cancer treatment was undertaken and type of loco-regional therapy. 
Conclusions: Late diagnosis, deprivation and differential access to and quality of cancer care services were the key contributors to ethnic disparities in breast cancer survival in New Zealand. Our findings underscore the need for a greater equity focus along the breast cancer care pathway, with an emphasis on improving access to early diagnosis for Maori and Pacific women.

text: Ethnic disparities in breast cancer survival in New Zealand: which factors contribute? Background: New Zealand has major ethnic disparities in breast cancer survival with Maori (indigenous people) and Pacific women (immigrants or descended from immigrants from Pacific Islands) faring much worse than other ethnic groups. This paper identified underlying factors and assessed their relative contribution to this risk differential. 
Methods: This study involved all women who were diagnosed with primary invasive breast cancer in two health regions, covering about 40% of the national population, between January 2000 and June 2014. Maori and Pacific patients were compared with other ethnic groups in terms of demographics, mode of diagnosis, disease factors and treatment factors. Cox regression modelling was performed with stepwise adjustments, and hazards of excess mortality from breast cancer for Maori and Pacific patients were assessed. 
Results: Of the 13,657 patients who were included in this analysis, 1281 (9.4%) were Maori, and 897 (6.6%) were Pacific women. Compared to other ethnic groups, they were younger, more likely to reside in deprived neighbourhoods and to have co-morbidities, and less likely to be diagnosed through screening and with early stage cancer, to be treated in a private care facility, to receive timely cancer treatment, and to receive breast conserving surgery. They had a higher risk of excess mortality from breast cancer (age and year of diagnosis adjusted hazard ratio: 1.76; 95% CI: 1.51-2.04 for Maori and 1.97; 95% CI: 1.67-2.32 for Pacific women), of which 75% and 99% respectively were explained by baseline differences. The most important contributor was late stage at diagnosis. Other contributors included neighbourhood deprivation, mode of diagnosis, type of health care facility where primary cancer treatment was undertaken and type of loco-regional therapy. 
Conclusions: Late diagnosis, deprivation and differential access to and quality of cancer care services were the key contributors to ethnic disparities in breast cancer survival in New Zealand. Our findings underscore the need for a greater equity focus along the breast cancer care pathway, with an emphasis on improving access to early diagnosis for Maori and Pacific women.

year: 2018