title: Economic Valuation of Water Quality Improvements in New Zealand

authors: Mkwara, Lena Asimenye

subjects: Water quality

abstract: Efficient decision making in environmental management requires good data on the costs and benefits of changes in environmental quality. However, full assessment of the benefits of better water quality has been a challenge because some of the component values cannot be directly measured. The advent of non-market valuation techniques has made it possible to estimate these values. In this thesis, the travel cost random utility model and fishing choice data from the National Angling Survey are used to assess the benefits of better water quality for trout anglers in the Rotorua Lakes and a choice experiment is used to assess the benefits of cleaner streams for Karapiro catchment residents. We also explore three methodological aspects which may affect non market value estimates, namely within season variability, scale heterogeneity across individuals and respondent perceptions of the status quo.

Accounting for within-season variability in site attributes that are variable across the season may reduce multicollinearity. We find that differences in welfare estimates between models accounting for within-season variability and those that do not may result from differences in attribute and collinearity levels or the combined effect of both. We assess whether benefit estimates remain stable over time using models that account for scale heterogeneity across individuals and demonstrate that ignoring scale heterogeneity across the sampled population may result in researchers erroneously concluding that estimates of marginal willingness to pay are stable over time. A choice experiment on preferences for stream water quality is used to assess the effects of respondent’s perception of status quo conditions on welfare estimates. The results build on earlier findings which suggest that failure to take account of respondents’ beliefs leads to biased welfare estimates.

Overall we find that lakes with better water clarity, that are larger in size, with bigger fish, more facilities and more forest cover are preferred. Similarly, streams with water quality that is suitable for swimming and where trout are found, are preferred. We estimate the aggregate annual benefit for anglers of a one metre increase in water clarity in all the Rotorua Lakes which currently have poor or average water water quality to be NZ$2.3 million. The travel cost RUM is also used to assess the overall benefit that trout anglers obtain from each lake. The annual level of these benefits totals NZ$21.7 million.

text: Economic Valuation of Water Quality Improvements in New Zealand Efficient decision making in environmental management requires good data on the costs and benefits of changes in environmental quality. However, full assessment of the benefits of better water quality has been a challenge because some of the component values cannot be directly measured. The advent of non-market valuation techniques has made it possible to estimate these values. In this thesis, the travel cost random utility model and fishing choice data from the National Angling Survey are used to assess the benefits of better water quality for trout anglers in the Rotorua Lakes and a choice experiment is used to assess the benefits of cleaner streams for Karapiro catchment residents. We also explore three methodological aspects which may affect non market value estimates, namely within season variability, scale heterogeneity across individuals and respondent perceptions of the status quo.

Accounting for within-season variability in site attributes that are variable across the season may reduce multicollinearity. We find that differences in welfare estimates between models accounting for within-season variability and those that do not may result from differences in attribute and collinearity levels or the combined effect of both. We assess whether benefit estimates remain stable over time using models that account for scale heterogeneity across individuals and demonstrate that ignoring scale heterogeneity across the sampled population may result in researchers erroneously concluding that estimates of marginal willingness to pay are stable over time. A choice experiment on preferences for stream water quality is used to assess the effects of respondent’s perception of status quo conditions on welfare estimates. The results build on earlier findings which suggest that failure to take account of respondents’ beliefs leads to biased welfare estimates.

Overall we find that lakes with better water clarity, that are larger in size, with bigger fish, more facilities and more forest cover are preferred. Similarly, streams with water quality that is suitable for swimming and where trout are found, are preferred. We estimate the aggregate annual benefit for anglers of a one metre increase in water clarity in all the Rotorua Lakes which currently have poor or average water water quality to be NZ$2.3 million. The travel cost RUM is also used to assess the overall benefit that trout anglers obtain from each lake. The annual level of these benefits totals NZ$21.7 million.

year: 2015

title: Review: Extrusion processing and properties of protein-based thermoplastics

authors: Verbeek, Casparus Johan R.

subjects: extrusion

abstract: Increasing interest in competitive, sustainable, and biodegradable alternatives to petroleum-based plastics has encouraged the development of protein-based plastics. The formation of a homogeneous protein melt during extrusion occurs through: denaturation, dissociation, unraveling, and alignment of polymer chains. The presence of covalent cross-links is unfavorable, decreasing chain mobility, increasing viscosity and preventing homogenization. Proteins have high softening temperatures, often above their decomposition temperatures. To avoid degradation, the required chain mobility is achieved by plasticizers. By understanding a protein's physiochemical nature, additives can be selected that lead to a bioplastic with good processability. The final structural and functional properties are highly dependent on the protein and processing conditions.

text: Review: Extrusion processing and properties of protein-based thermoplastics Increasing interest in competitive, sustainable, and biodegradable alternatives to petroleum-based plastics has encouraged the development of protein-based plastics. The formation of a homogeneous protein melt during extrusion occurs through: denaturation, dissociation, unraveling, and alignment of polymer chains. The presence of covalent cross-links is unfavorable, decreasing chain mobility, increasing viscosity and preventing homogenization. Proteins have high softening temperatures, often above their decomposition temperatures. To avoid degradation, the required chain mobility is achieved by plasticizers. By understanding a protein's physiochemical nature, additives can be selected that lead to a bioplastic with good processability. The final structural and functional properties are highly dependent on the protein and processing conditions.

year: 2010

title: Teaching te reo Māori as a second language in primary schools: two case studies.

authors: Hill, Richard Kenneth

subjects: second languages

abstract: The provision of second language education in New Zealand primary schools has been, until recently, a rare addition to programmes. Its wider implementation in New Zealand primary schools has always been limited by low numbers of fluent bilingual teachers, and a perception that in a predominantly English speaking country such as New Zealand there is no need to teach additional languages in primary schools. The New Zealand Curriculum (Ministry of Education, 2007) provides the first opportunity to formally include second language education in primary schools, and to establish the learning of second languages as a worthwhile pursuit in New Zealand. However, the success of such a policy change will depend on the ability of the Ministry of Education and course providers to upskill teachers in their ability to speak additional languages and teach them. This article reports on the outcomes of a Ministry-funded project designed to strengthen the second language teaching approaches of upper primary school teachers who teach te reo Maori. It provides case studies of two of the teachers who completed this course, and finds that while there are clear benefits to be derived from such teacher professional development courses, these courses need to focus on long-term objectives and be channelled to those teachers and students who stand to benefit the most from professional development courses.

text: Teaching te reo Māori as a second language in primary schools: two case studies. The provision of second language education in New Zealand primary schools has been, until recently, a rare addition to programmes. Its wider implementation in New Zealand primary schools has always been limited by low numbers of fluent bilingual teachers, and a perception that in a predominantly English speaking country such as New Zealand there is no need to teach additional languages in primary schools. The New Zealand Curriculum (Ministry of Education, 2007) provides the first opportunity to formally include second language education in primary schools, and to establish the learning of second languages as a worthwhile pursuit in New Zealand. However, the success of such a policy change will depend on the ability of the Ministry of Education and course providers to upskill teachers in their ability to speak additional languages and teach them. This article reports on the outcomes of a Ministry-funded project designed to strengthen the second language teaching approaches of upper primary school teachers who teach te reo Maori. It provides case studies of two of the teachers who completed this course, and finds that while there are clear benefits to be derived from such teacher professional development courses, these courses need to focus on long-term objectives and be channelled to those teachers and students who stand to benefit the most from professional development courses.

year: 2010