title: Distribution of willingness-to-pay for speed reduction with non-positive bidders: Is choice modelling consistent with contingent valuation?

authors: Scarpa, Riccardo

subjects: contingent valuation

abstract: The paper addresses the issue of consistency between two commonly employed stated preference data—referendum contingent valuation (CV) and discrete choice modelling (CM)—with respect to estimated distributions of individual willingness-to-pay (WTP) for non-market goods. The policy context is that of a local externality: effective speed reduction by means of traffic-calming in towns crossed by fast roads. In particular, data from two independent samples of the same population are contrasted. The findings show that both methods indicate that speed reduction via traffic-calming is valued in a polarized fashion. Results from both methods are consistent with the presence of two groups of preferences: a larger group holding positive values and a smaller one with non-positive values. While the estimates of the relative proportions of the two groups are similar across the two data sources, once the econometric analysis of the CM responses allows for polarized preferences the estimates of the distribution of individual WTP differ substantially. The results from the choice modelling survey indicate that residents are also willing to pay for other benefits from traffic-calming, such as noise reduction and a decreased waiting time for crossing, but preferences for these are also polarized, with WTP for aesthetic improvements being positive only for those supporting effective speed control. In comparing distributions of value estimates from CM and CV, surveys practitioners should account for the effects of taste heterogeneity over externalities and take advantage of the ability to derive individual-specific WTP estimates from panel estimation rather than simply deriving estimates for common features of the WTP distribution.

text: Distribution of willingness-to-pay for speed reduction with non-positive bidders: Is choice modelling consistent with contingent valuation? The paper addresses the issue of consistency between two commonly employed stated preference data—referendum contingent valuation (CV) and discrete choice modelling (CM)—with respect to estimated distributions of individual willingness-to-pay (WTP) for non-market goods. The policy context is that of a local externality: effective speed reduction by means of traffic-calming in towns crossed by fast roads. In particular, data from two independent samples of the same population are contrasted. The findings show that both methods indicate that speed reduction via traffic-calming is valued in a polarized fashion. Results from both methods are consistent with the presence of two groups of preferences: a larger group holding positive values and a smaller one with non-positive values. While the estimates of the relative proportions of the two groups are similar across the two data sources, once the econometric analysis of the CM responses allows for polarized preferences the estimates of the distribution of individual WTP differ substantially. The results from the choice modelling survey indicate that residents are also willing to pay for other benefits from traffic-calming, such as noise reduction and a decreased waiting time for crossing, but preferences for these are also polarized, with WTP for aesthetic improvements being positive only for those supporting effective speed control. In comparing distributions of value estimates from CM and CV, surveys practitioners should account for the effects of taste heterogeneity over externalities and take advantage of the ability to derive individual-specific WTP estimates from panel estimation rather than simply deriving estimates for common features of the WTP distribution.

year: 2006

title: Understanding the beliefs and behaviours of low-skilled adults as they re-engage with mathematics

authors: Whitten, Damon Rodger

subjects: Adult numeracy

abstract: This thesis explored low-skilled adult learners’ beliefs about mathematics and how they engaged with mathematical content delivered as part of foundation-level vocational programmes in New Zealand. It also examined how low-skilled learners holding procedurally-oriented beliefs responded to a classroom environment that emphasised conceptual understanding, collaboration and discourse. An ‘insider research’ approach was adopted to capitalise on the researcher’s prior experience in the sector. Analysis of data utilised an interpretive approach drawing on Bandura’s triadic reciprocal determinant model that posited beliefs, behaviour and the environment as interacting factors. Methods of data collection included surveys, observations, interviews and an intervention in which the researcher took a dual tutor/researcher role. Observation and intervention data were collected through multiple audio-recording devices that recorded private and public utterances as learners participated in lessons.

The survey and interview findings showed that most low-skilled adults believed mathematics to be procedural, performance-oriented, and learned by adopting passive strategies. Many held non-mathematical identities, described school and foundation-level mathematics lessons as potentially shame making, and reported censoring their behaviours to avoid shame.

The use of multiple-recording devices was effective for capturing the complexity of classroom interactions. Learners’ behaviours within lessons were consistent with procedural/calculational beliefs and reflected performance-oriented goals such as completing tasks quickly and accurately. Some learners displayed negative affective responses when expected to engage with mathematical content, and adopted behaviours designed to reduce, or eliminate, public exposure to failure. Group problem-solving was characterised by an unequal division of labour between ‘solvers’ and ‘supporters’. Lower-skilled learners tended to adopt peripheral support roles, while procedurally proficient learners either took, or were assigned, responsibility for all mathematical thinking. These behaviours enabled groups to complete tasks and achieve pseudo-success yet constrained the lower-skilled learners’ engagement in mathematical thinking, while also presenting little mathematical challenge to higher-skilled learners. This pattern appeared to contribute to the maintenance of learners’ low skills and non-mathematical identities by routinising their deferral of agency to more proficient learners.

The intervention indicated that low-skilled procedurally-oriented learners tended to resist conceptually-oriented activities that emphasised mathematical discourse, collaboration, and inquiry. This appeared to be because these activities increased the threat of a shameful episode and were perceived as superfluous to their procedurally-oriented goals. Learners reported that the intervention was more effective than their traditional classes, but attributed this to better tutor explanations, rather than their own active engagement in mathematical thinking. The overall findings indicated that low-skilled procedurally-oriented adults preferred and expected a traditional approach, and many used its familiar routines to reduce their level of engagement and exposure to shame. Implications for educators include the need to differentiate authentic from pseudo-engagement, to understand the impact of shame on behaviour, and establish positive patterns of engagement.

text: Understanding the beliefs and behaviours of low-skilled adults as they re-engage with mathematics This thesis explored low-skilled adult learners’ beliefs about mathematics and how they engaged with mathematical content delivered as part of foundation-level vocational programmes in New Zealand. It also examined how low-skilled learners holding procedurally-oriented beliefs responded to a classroom environment that emphasised conceptual understanding, collaboration and discourse. An ‘insider research’ approach was adopted to capitalise on the researcher’s prior experience in the sector. Analysis of data utilised an interpretive approach drawing on Bandura’s triadic reciprocal determinant model that posited beliefs, behaviour and the environment as interacting factors. Methods of data collection included surveys, observations, interviews and an intervention in which the researcher took a dual tutor/researcher role. Observation and intervention data were collected through multiple audio-recording devices that recorded private and public utterances as learners participated in lessons.

The survey and interview findings showed that most low-skilled adults believed mathematics to be procedural, performance-oriented, and learned by adopting passive strategies. Many held non-mathematical identities, described school and foundation-level mathematics lessons as potentially shame making, and reported censoring their behaviours to avoid shame.

The use of multiple-recording devices was effective for capturing the complexity of classroom interactions. Learners’ behaviours within lessons were consistent with procedural/calculational beliefs and reflected performance-oriented goals such as completing tasks quickly and accurately. Some learners displayed negative affective responses when expected to engage with mathematical content, and adopted behaviours designed to reduce, or eliminate, public exposure to failure. Group problem-solving was characterised by an unequal division of labour between ‘solvers’ and ‘supporters’. Lower-skilled learners tended to adopt peripheral support roles, while procedurally proficient learners either took, or were assigned, responsibility for all mathematical thinking. These behaviours enabled groups to complete tasks and achieve pseudo-success yet constrained the lower-skilled learners’ engagement in mathematical thinking, while also presenting little mathematical challenge to higher-skilled learners. This pattern appeared to contribute to the maintenance of learners’ low skills and non-mathematical identities by routinising their deferral of agency to more proficient learners.

The intervention indicated that low-skilled procedurally-oriented learners tended to resist conceptually-oriented activities that emphasised mathematical discourse, collaboration, and inquiry. This appeared to be because these activities increased the threat of a shameful episode and were perceived as superfluous to their procedurally-oriented goals. Learners reported that the intervention was more effective than their traditional classes, but attributed this to better tutor explanations, rather than their own active engagement in mathematical thinking. The overall findings indicated that low-skilled procedurally-oriented adults preferred and expected a traditional approach, and many used its familiar routines to reduce their level of engagement and exposure to shame. Implications for educators include the need to differentiate authentic from pseudo-engagement, to understand the impact of shame on behaviour, and establish positive patterns of engagement.

year: 2018

title: An investigation into the commercial feasibility of Jasus edwardsii aquaculture in New Zealand

authors: Ruru, Ian Hector

subjects: New Zealand

abstract: In 1996 New Zealand introduced legislation to allow Jasus edwardsii pueruli to be collected as "seedstock" and ongrown in a commercial aquaculture trial. The aim of this thesis was to investigate the commercial feasibility of J. edwardsii aquaculture in New Zealand by working with an organisation involved in the trial.
The methodology involved a combination of experiments in the field, in laboratories, and within an ongrowing facility. This thesis examined five key areas and found the following:
1. Data obtained in the research indicates that New Zealand will continue to rely on harvesting pueruli from the wild since significant technical obstacles remain in the development of commercial scale pueruli hatcheries. Forecast data, obtained using the delphi technique and information about current research on larval rearing, indicates that commercial scale supply of pueruli from hatcheries may occur between 2017 and 2021.
2. Harvesting trials collected a low number of pueruli with the lowest unit cost for collection being $1.80. A greater collection rate could be achieved with a better understanding of seasonal and local settlement patterns.
3. Survival rates in pueruli transporting experiments were significantly affected by stocking density, time and temperature. The safest transit conditions were achieved with 15 pueruli per litre for less than 6 hours at 14°C.
4. A range of stocking densities, from 3 lobsters per tank to 12 per tank, were tested for their effect on growth of six-month old lobsters. The lobsters were reared in a total recirculation seawater system at a constant 16°C, and fed fresh mussels (Perna canaliculus). For the 121 day trial, no statistically significant effect was detected. However, there was a trend for growth rates to be highest at 3 and 6 lobsters per tank and for growth rates at stocking densities of 9 and 12 lobsters per tank to decrease after Day 50. Lobsters showed increased mortality at the highest stocking rate.
5. A bioeconomic model of a hypothetical farm was developed to assess economic benefits and risks and to determine overall profitability. The model showed an annual net cash position of $287,100 and cumulative cash position of $859,200 by the 10th year of operation based on annual sales of 10,837 kg at $65 per kg. The model indicates that the highest cost components in the first 10 years are processing and transport, and labour. Based on the model and the scenarios examined, profitability is very sensitive to factors such as the farm size, processing and transport costs, and sale price. Biological factors such as growth rates, survival, and feed requirements also influence overall profitability. Good returns will depend upon consistent exports of high quality lobsters.
The study concludes that commercial feasibility will be affected by these key areas. The potential of J. edwardsii aquaculture in New Zealand will continue to benefit from further research.

text: An investigation into the commercial feasibility of Jasus edwardsii aquaculture in New Zealand In 1996 New Zealand introduced legislation to allow Jasus edwardsii pueruli to be collected as "seedstock" and ongrown in a commercial aquaculture trial. The aim of this thesis was to investigate the commercial feasibility of J. edwardsii aquaculture in New Zealand by working with an organisation involved in the trial.
The methodology involved a combination of experiments in the field, in laboratories, and within an ongrowing facility. This thesis examined five key areas and found the following:
1. Data obtained in the research indicates that New Zealand will continue to rely on harvesting pueruli from the wild since significant technical obstacles remain in the development of commercial scale pueruli hatcheries. Forecast data, obtained using the delphi technique and information about current research on larval rearing, indicates that commercial scale supply of pueruli from hatcheries may occur between 2017 and 2021.
2. Harvesting trials collected a low number of pueruli with the lowest unit cost for collection being $1.80. A greater collection rate could be achieved with a better understanding of seasonal and local settlement patterns.
3. Survival rates in pueruli transporting experiments were significantly affected by stocking density, time and temperature. The safest transit conditions were achieved with 15 pueruli per litre for less than 6 hours at 14°C.
4. A range of stocking densities, from 3 lobsters per tank to 12 per tank, were tested for their effect on growth of six-month old lobsters. The lobsters were reared in a total recirculation seawater system at a constant 16°C, and fed fresh mussels (Perna canaliculus). For the 121 day trial, no statistically significant effect was detected. However, there was a trend for growth rates to be highest at 3 and 6 lobsters per tank and for growth rates at stocking densities of 9 and 12 lobsters per tank to decrease after Day 50. Lobsters showed increased mortality at the highest stocking rate.
5. A bioeconomic model of a hypothetical farm was developed to assess economic benefits and risks and to determine overall profitability. The model showed an annual net cash position of $287,100 and cumulative cash position of $859,200 by the 10th year of operation based on annual sales of 10,837 kg at $65 per kg. The model indicates that the highest cost components in the first 10 years are processing and transport, and labour. Based on the model and the scenarios examined, profitability is very sensitive to factors such as the farm size, processing and transport costs, and sale price. Biological factors such as growth rates, survival, and feed requirements also influence overall profitability. Good returns will depend upon consistent exports of high quality lobsters.
The study concludes that commercial feasibility will be affected by these key areas. The potential of J. edwardsii aquaculture in New Zealand will continue to benefit from further research.

year: 2000