title: Past research on the impact of international migration on house prices: Implications for Auckland

authors: Cochrane, William

abstract: While conducting a strategic review of the New Zealand immigration system in terms of assessing its contribution to economic growth, the Ministry of Business Innovation and Employment (MBIE) noted that “some people are of the view that increases in net migration are impacting the housing market and infrastructure, especially in Auckland……” and that “at this point in time, there is no conclusive evidence supporting these concerns….”. While MBIE has done some recent work in this area, the focus has tended to be on New Zealand as a whole. MBIE wanted therefore to advance this work with a specific focus on the impact of net international migration (usually measured as the difference between permanent and long term (PLT) departures and PLT arrivals) and, where possible, visa-controlled immigration (i.e. the numbers of people granted temporary or permanent visas) on the Auckland housing market. To this end MBIE engaged the University of Waikato to produce a concise review of the conclusions that can be drawn from the recent international and New Zealand literatures regarding the impact of net international migration on housing markets. The emphasis is of course on conclusions that would be relevant for, or that can be directly applied to, the Auckland housing market. This note provides this concise review of the literature. Trends in relevant core statistical indicators are also provided.
To focus the review, the following six hypotheses were considered (our conclusion concerning the veracity of the hypothesis in terms of available evidence in the literature is stated in bold):
1. The decrease of New Zealanders leaving in recent years, due to relatively strong economic growth and a subdued Australian economy, has had a bigger impact on rising house prices in Auckland than the growing number of migrants settling in Auckland. 
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
2. The contribution of the inflow of Australians and of returning New Zealanders to population growth in Auckland has had a bigger impact on house price increases than other permanent and long-term (PLT) arrivals.
𝐈𝐧𝐜𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐯𝐞
3. Current and recent (5 years previous) net international migration trends (considering both PLT arrivals and departures) have had a minor impact on the Auckland housing market, relative to other factors.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
4. Investor migrants are not having a disproportionate impact on the Auckland housing market as they are purchasing largely commercial property or a single individual residence.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
5. Until comprehensive data become available on country of residence of buyers and sellers at the time of a sale, it cannot be established conclusively that offshore investors drive up house prices in particular areas in central Auckland.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
6. Given the above and the time lags between immigration policy changes and impacts, it is unlikely to be useful to make changes to immigration policy to dampen Auckland house prices.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
Overall we find that the literature and the available data on population change suggest that visa-controlled immigration into New Zealand, and specifically into Auckland, in the recent past has had a relatively small impact on house prices compared to other demand factors, such as the strongly cyclical changes in the emigration of New Zealanders, low interest rates, investor demand and capital gains expectations. Consequently, changes in immigration policy, which can impact only on visa-controlled immigration, are unlikely to have much impact on the housing market.

text: Past research on the impact of international migration on house prices: Implications for Auckland While conducting a strategic review of the New Zealand immigration system in terms of assessing its contribution to economic growth, the Ministry of Business Innovation and Employment (MBIE) noted that “some people are of the view that increases in net migration are impacting the housing market and infrastructure, especially in Auckland……” and that “at this point in time, there is no conclusive evidence supporting these concerns….”. While MBIE has done some recent work in this area, the focus has tended to be on New Zealand as a whole. MBIE wanted therefore to advance this work with a specific focus on the impact of net international migration (usually measured as the difference between permanent and long term (PLT) departures and PLT arrivals) and, where possible, visa-controlled immigration (i.e. the numbers of people granted temporary or permanent visas) on the Auckland housing market. To this end MBIE engaged the University of Waikato to produce a concise review of the conclusions that can be drawn from the recent international and New Zealand literatures regarding the impact of net international migration on housing markets. The emphasis is of course on conclusions that would be relevant for, or that can be directly applied to, the Auckland housing market. This note provides this concise review of the literature. Trends in relevant core statistical indicators are also provided.
To focus the review, the following six hypotheses were considered (our conclusion concerning the veracity of the hypothesis in terms of available evidence in the literature is stated in bold):
1. The decrease of New Zealanders leaving in recent years, due to relatively strong economic growth and a subdued Australian economy, has had a bigger impact on rising house prices in Auckland than the growing number of migrants settling in Auckland. 
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
2. The contribution of the inflow of Australians and of returning New Zealanders to population growth in Auckland has had a bigger impact on house price increases than other permanent and long-term (PLT) arrivals.
𝐈𝐧𝐜𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐯𝐞
3. Current and recent (5 years previous) net international migration trends (considering both PLT arrivals and departures) have had a minor impact on the Auckland housing market, relative to other factors.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
4. Investor migrants are not having a disproportionate impact on the Auckland housing market as they are purchasing largely commercial property or a single individual residence.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
5. Until comprehensive data become available on country of residence of buyers and sellers at the time of a sale, it cannot be established conclusively that offshore investors drive up house prices in particular areas in central Auckland.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
6. Given the above and the time lags between immigration policy changes and impacts, it is unlikely to be useful to make changes to immigration policy to dampen Auckland house prices.
𝐒𝐮𝐩𝐩𝐨𝐫𝐭𝐞𝐝
Overall we find that the literature and the available data on population change suggest that visa-controlled immigration into New Zealand, and specifically into Auckland, in the recent past has had a relatively small impact on house prices compared to other demand factors, such as the strongly cyclical changes in the emigration of New Zealanders, low interest rates, investor demand and capital gains expectations. Consequently, changes in immigration policy, which can impact only on visa-controlled immigration, are unlikely to have much impact on the housing market.

year: 2016

title: Evaluation of granular media to wastewater treatment; advanced primary treatment utilising modified pumice, titanomagnetite and ceramic nozzles.

authors: Blättler, Anna

abstract: The treatment of wastewater to higher standards is becoming increasingly important as legislation and public perception demand reduced impact of human activity on the environment. Filtration of primary treated effluent (PTE) and secondary treated effluent (STE) offers a possible sustainable technology for meeting or partially meeting these demands.

Granular media filtration, if used at all, is typically incorporated in wastewater treatment as a polishing step following secondary biological treatment and flocculation. The use of filtration following primary sedimentation has not been practised widely. The objective of this research was to investigate the feasibility of filtering PTE using New Zealand’s indigenous volcanic deposits as filter media in a recently developed dual media filtration system incorporating porous ceramic nozzles. The two media types studied included titanomagnetite (TM) and Silicon Sponge (SS). Titanomagnetite is an ironsand concentrate with a very fine grain size (0.07 to 0.18mm). Silicon Sponge is abraded river pumice and was available in two sizes: SS 14/24 (0.6 to 1 mm) and SS 7 /14 (0.4 to 2 mm). The surface of TM grains is smooth and that of SS is highly porous due to the vesiculated structure of pumice, while maintaining a low abrasive factor.

In order to test filtration behaviour of TM and SS media, bench-scale experiments, using glass columns were performed. A model effluent was prepared from reconstituted dairy farm manure. Suspended particle sizes in farm dairy effluent (FDE) were similar to those measured for PTE. Most of the bench trials used FDE. Filtration trends were easy monitored by turbidity reduction. About 50% of FDE turbidity was removed by 100 mm TM columns. TM performance was improved by the addition of TM fines but flows were reduced. Unmodified TM retained most particles larger than 5 µm. This would likely to remove protozoa such as giardia and cryptosporidium. The effect of pH on turbidity removal by TM beds was significant. Turbidity removal increased from 40 to 80% upon the lowering of the effluent pH from 6.5 to 3.5. Raising the pH above 6.5 had no effect. No pH-induced change in particle size distribution of the effluent was observed. A pH of 3.5 is below the isoelectric point of TM and it is likely that the enhanced turbidity removal was due to electrostatic effects.

In bench-scale filtration of PTE at pH 6.5, a 100 mm depth of TM removed 30% of the turbidity. Increasing the bed depth for TM did not lead to significant further improvement in filter performance. In the case of filtration by a fine SS (14/24), 25% turbidity removal was achieved using a 500 mm bed. Increasing the bed depth to 1800 mm increased turbidity removal to 50%. In glass column experiments, a 1000 mm deep bed of coarse SS (7 /14) removed 30% of the turbidity. An increase to 35% occurred when the bed depth, using this medium was increased to 1600 mm. The same media when used in larger pilot plant filters removed 50% of the turbidity. A particular feature of the TM medium was its ease of fluidisation at flowrates < 10 m/h. This characteristics make it a suitable medium for pulsed bed operation. A feature of the SS medium was its large hydraulic conductivity and high solids holding capacity.

On the basis of the results obtained from the bench trials, evaluation filter units incorporating the essential features of the porous ceramic dual media (PCDM) system were constructed. The evaluation systems were equipped with under drains that incorporated a variety of purpose designed titanomagnetite ceramic (TMC) nozzles held in place by a tube bolt that also delivered air and water during filtration and backwashing. Investigation of the flow characteristics of the TMC nozzles showed that the major flow-regulating factor in the nozzle system was the water orifice in the bolt stem. Resistance in up-flow was consistently larger than resistance in down-flow. This was attributed to differences in the hydrodynamics of flow in each direction. Re-designing the bolt could lead to a 30% reduced flow-restriction during backwashing.

Biofilm growth on the TM and SS filtration media and the TMC used to manufacture the ceramic nozzles was studied by prolonged immersion in partially digested effluent. SS media showed a high degree of vesicular space and under aerobic conditions, affinity for loose attachment of organic material. TM showed most anaerobic film growth, accompanied by formation of a red iron oxide deposit. Significantly little biofilm growth on the ceramic material was observed. Such growth, if it occurred, could block the nozzles.
Pilot plant evaluation trials using PTE showed that for SS, filtration efficiency increased steeply with bed depth up to a bed depth of 500 mm, irrespective of the grade of SS used. At depths greater than 500 mm, filtration efficiency increased more slowly with depth. Run times were typically of 50 h duration by which time flow rates under a constant head of 2700 mm had decreased from 12 m/h to 1 m/h. Bed loadings were as high as 100 kg/m³ at the top of the bed with a mean of 22 kg/m³. In the case of TM, a minimum bed depth of 100 mm was required in order to accommodate the TMC tube nozzles. Deeper beds blocked after very short run times. Flowrates of 1 m/h or less and run times of 1 h or less were observed.

For both types of media, solids were easily dislodged during backwashing.

Pulsed backwashing greatly reduced backwash water requirements and in the case of SS beds yielded sludge with solids content suitable for anaerobic digestion. 

Flow-dynamics through PCDM filter nozzles showed increased resistance in upflow being caused by designs in the nozzle-bolt. Vena contracta effects provide an explanation. 

PCDM filtration using SS as the major medium offers a viable technology for the continuous removal of much of the TSS from PTE. A potential energy saving can be envisaged from the reduced aeration required for reduced BOD loadings going to secondary biological treatment. In addition, the concentrated backwash water from bed backwashing, can be transferred directly to anaerobic digesters. Reduced CO₂ generation and an increase in methane production would off-set installation and running costs of the filter in about 15 years.

text: Evaluation of granular media to wastewater treatment; advanced primary treatment utilising modified pumice, titanomagnetite and ceramic nozzles. The treatment of wastewater to higher standards is becoming increasingly important as legislation and public perception demand reduced impact of human activity on the environment. Filtration of primary treated effluent (PTE) and secondary treated effluent (STE) offers a possible sustainable technology for meeting or partially meeting these demands.

Granular media filtration, if used at all, is typically incorporated in wastewater treatment as a polishing step following secondary biological treatment and flocculation. The use of filtration following primary sedimentation has not been practised widely. The objective of this research was to investigate the feasibility of filtering PTE using New Zealand’s indigenous volcanic deposits as filter media in a recently developed dual media filtration system incorporating porous ceramic nozzles. The two media types studied included titanomagnetite (TM) and Silicon Sponge (SS). Titanomagnetite is an ironsand concentrate with a very fine grain size (0.07 to 0.18mm). Silicon Sponge is abraded river pumice and was available in two sizes: SS 14/24 (0.6 to 1 mm) and SS 7 /14 (0.4 to 2 mm). The surface of TM grains is smooth and that of SS is highly porous due to the vesiculated structure of pumice, while maintaining a low abrasive factor.

In order to test filtration behaviour of TM and SS media, bench-scale experiments, using glass columns were performed. A model effluent was prepared from reconstituted dairy farm manure. Suspended particle sizes in farm dairy effluent (FDE) were similar to those measured for PTE. Most of the bench trials used FDE. Filtration trends were easy monitored by turbidity reduction. About 50% of FDE turbidity was removed by 100 mm TM columns. TM performance was improved by the addition of TM fines but flows were reduced. Unmodified TM retained most particles larger than 5 µm. This would likely to remove protozoa such as giardia and cryptosporidium. The effect of pH on turbidity removal by TM beds was significant. Turbidity removal increased from 40 to 80% upon the lowering of the effluent pH from 6.5 to 3.5. Raising the pH above 6.5 had no effect. No pH-induced change in particle size distribution of the effluent was observed. A pH of 3.5 is below the isoelectric point of TM and it is likely that the enhanced turbidity removal was due to electrostatic effects.

In bench-scale filtration of PTE at pH 6.5, a 100 mm depth of TM removed 30% of the turbidity. Increasing the bed depth for TM did not lead to significant further improvement in filter performance. In the case of filtration by a fine SS (14/24), 25% turbidity removal was achieved using a 500 mm bed. Increasing the bed depth to 1800 mm increased turbidity removal to 50%. In glass column experiments, a 1000 mm deep bed of coarse SS (7 /14) removed 30% of the turbidity. An increase to 35% occurred when the bed depth, using this medium was increased to 1600 mm. The same media when used in larger pilot plant filters removed 50% of the turbidity. A particular feature of the TM medium was its ease of fluidisation at flowrates < 10 m/h. This characteristics make it a suitable medium for pulsed bed operation. A feature of the SS medium was its large hydraulic conductivity and high solids holding capacity.

On the basis of the results obtained from the bench trials, evaluation filter units incorporating the essential features of the porous ceramic dual media (PCDM) system were constructed. The evaluation systems were equipped with under drains that incorporated a variety of purpose designed titanomagnetite ceramic (TMC) nozzles held in place by a tube bolt that also delivered air and water during filtration and backwashing. Investigation of the flow characteristics of the TMC nozzles showed that the major flow-regulating factor in the nozzle system was the water orifice in the bolt stem. Resistance in up-flow was consistently larger than resistance in down-flow. This was attributed to differences in the hydrodynamics of flow in each direction. Re-designing the bolt could lead to a 30% reduced flow-restriction during backwashing.

Biofilm growth on the TM and SS filtration media and the TMC used to manufacture the ceramic nozzles was studied by prolonged immersion in partially digested effluent. SS media showed a high degree of vesicular space and under aerobic conditions, affinity for loose attachment of organic material. TM showed most anaerobic film growth, accompanied by formation of a red iron oxide deposit. Significantly little biofilm growth on the ceramic material was observed. Such growth, if it occurred, could block the nozzles.
Pilot plant evaluation trials using PTE showed that for SS, filtration efficiency increased steeply with bed depth up to a bed depth of 500 mm, irrespective of the grade of SS used. At depths greater than 500 mm, filtration efficiency increased more slowly with depth. Run times were typically of 50 h duration by which time flow rates under a constant head of 2700 mm had decreased from 12 m/h to 1 m/h. Bed loadings were as high as 100 kg/m³ at the top of the bed with a mean of 22 kg/m³. In the case of TM, a minimum bed depth of 100 mm was required in order to accommodate the TMC tube nozzles. Deeper beds blocked after very short run times. Flowrates of 1 m/h or less and run times of 1 h or less were observed.

For both types of media, solids were easily dislodged during backwashing.

Pulsed backwashing greatly reduced backwash water requirements and in the case of SS beds yielded sludge with solids content suitable for anaerobic digestion. 

Flow-dynamics through PCDM filter nozzles showed increased resistance in upflow being caused by designs in the nozzle-bolt. Vena contracta effects provide an explanation. 

PCDM filtration using SS as the major medium offers a viable technology for the continuous removal of much of the TSS from PTE. A potential energy saving can be envisaged from the reduced aeration required for reduced BOD loadings going to secondary biological treatment. In addition, the concentrated backwash water from bed backwashing, can be transferred directly to anaerobic digesters. Reduced CO₂ generation and an increase in methane production would off-set installation and running costs of the filter in about 15 years.

year: 2002

title: Place responsive and culturally responsive outdoor education in secondary schools: Examining teachers' perspectives and experiences

authors: Skipworth, Andrew James

subjects: place responsive

abstract: Sustainability, place and human connectedness have increasingly become the focus of research and professional dialogue in school-based outdoor education in Aotearoa New Zealand. These developments challenge traditional practices that privilege adventure and individualistic outcomes in outdoor education. At the same time, the implementation of culturally responsive practices within many secondary schools has further challenged teachers of outdoor education to ensure that pedagogical approaches and outcomes meet the needs of their diverse student population. An increasing number of educators appear to have adopted place responsive and culturally responsive pedagogies within their outdoor education programmes or units of work at the senior school level, yet there is limited research examining teachers’ perceptions and experiences in doing so.
Adopting an interpretive framework, and using qualitative research methods, this research focuses on the challenges faced and opportunities presented when secondary school teachers in Aotearoa New Zealand adopt place and culturally responsive pedagogies in outdoor education. Six teachers of senior level outdoor education from schools spread throughout Aotearoa New Zealand shared their stories. An inductive analysis of the interviews identified these teachers faced ongoing challenges with adopting new pedagogies in outdoor education, which was in part because many colleagues held perceptions that outdoor education was less important than other subjects and was primarily about having fun. In addition, the complexities of assessment at the senior level meant that teachers often faced challenges in formally assessing student learning. Teachers also found that undertaking change required shifts in mind-set which were further supported by targeted professional development, engagement in post-graduate study and talking with like-minded teachers. However, teachers’ adoption of place and culturally responsive approaches generated notable opportunities to align to the front end of the New Zealand curriculum, promote the holistic development of students and nurture cultural diversity.
This study highlights that undertaking curriculum and pedagogical change in outdoor education in secondary schools is a complex process, which is greatly influenced by the attitudes and perceptions of others. The potential alignment of place responsive and culturally responsive pedagogies became apparent, as did the need for more targeted professional development for teachers of outdoor education. Teachers’ adoption of these pedagogies also highlighted a greater capacity for authentic outdoor education experiences for students that also strengthened a commitment to their bicultural partnerships in schools. As the nature of education changes in schools, contemporary pedagogies in outdoor education have the potential to enhance the capacity of schools to facilitate learning that will meet the diverse needs of learners in Aotearoa New Zealand.

text: Place responsive and culturally responsive outdoor education in secondary schools: Examining teachers' perspectives and experiences Sustainability, place and human connectedness have increasingly become the focus of research and professional dialogue in school-based outdoor education in Aotearoa New Zealand. These developments challenge traditional practices that privilege adventure and individualistic outcomes in outdoor education. At the same time, the implementation of culturally responsive practices within many secondary schools has further challenged teachers of outdoor education to ensure that pedagogical approaches and outcomes meet the needs of their diverse student population. An increasing number of educators appear to have adopted place responsive and culturally responsive pedagogies within their outdoor education programmes or units of work at the senior school level, yet there is limited research examining teachers’ perceptions and experiences in doing so.
Adopting an interpretive framework, and using qualitative research methods, this research focuses on the challenges faced and opportunities presented when secondary school teachers in Aotearoa New Zealand adopt place and culturally responsive pedagogies in outdoor education. Six teachers of senior level outdoor education from schools spread throughout Aotearoa New Zealand shared their stories. An inductive analysis of the interviews identified these teachers faced ongoing challenges with adopting new pedagogies in outdoor education, which was in part because many colleagues held perceptions that outdoor education was less important than other subjects and was primarily about having fun. In addition, the complexities of assessment at the senior level meant that teachers often faced challenges in formally assessing student learning. Teachers also found that undertaking change required shifts in mind-set which were further supported by targeted professional development, engagement in post-graduate study and talking with like-minded teachers. However, teachers’ adoption of place and culturally responsive approaches generated notable opportunities to align to the front end of the New Zealand curriculum, promote the holistic development of students and nurture cultural diversity.
This study highlights that undertaking curriculum and pedagogical change in outdoor education in secondary schools is a complex process, which is greatly influenced by the attitudes and perceptions of others. The potential alignment of place responsive and culturally responsive pedagogies became apparent, as did the need for more targeted professional development for teachers of outdoor education. Teachers’ adoption of these pedagogies also highlighted a greater capacity for authentic outdoor education experiences for students that also strengthened a commitment to their bicultural partnerships in schools. As the nature of education changes in schools, contemporary pedagogies in outdoor education have the potential to enhance the capacity of schools to facilitate learning that will meet the diverse needs of learners in Aotearoa New Zealand.

year: 2017