title: Agglomeration elasticities and firm heterogeneity

authors: Maré, David C.

subjects: agglomeration

abstract: This paper examines three key issues encountered when estimating the relationship between agglomeration and multi factor productivity ('agglomeration elasticities'): the sorting of heterogeneous firms, the convexity of agglomeration effects, and the challenges of identifying the impact of persistent spatial differences in effective density. We use a firm-level panel containing production data together with detailed information on the geographic location of employment, covering a high proportion of the New Zealand economy. We are able to control for heterogeneity along firm, region, and industry dimensions, and to estimate separate agglomeration elasticities across industries and regions. Sorting leads to upward biased elasticity estimates but using firm fixed effects can lead to downward bias due to the highly persistent nature of agglomeration variables. Our preferred estimates control for sorting across regions and industries. Overall, we find a positive agglomeration elasticity of 0.066. Within industries and, to a lesser extent within regions, there is pronounced variation in the strength of agglomeration effects, and evidence of decreasing returns to agglomeration. High density areas attract firms that benefit most from agglomeration.

text: Agglomeration elasticities and firm heterogeneity This paper examines three key issues encountered when estimating the relationship between agglomeration and multi factor productivity ('agglomeration elasticities'): the sorting of heterogeneous firms, the convexity of agglomeration effects, and the challenges of identifying the impact of persistent spatial differences in effective density. We use a firm-level panel containing production data together with detailed information on the geographic location of employment, covering a high proportion of the New Zealand economy. We are able to control for heterogeneity along firm, region, and industry dimensions, and to estimate separate agglomeration elasticities across industries and regions. Sorting leads to upward biased elasticity estimates but using firm fixed effects can lead to downward bias due to the highly persistent nature of agglomeration variables. Our preferred estimates control for sorting across regions and industries. Overall, we find a positive agglomeration elasticity of 0.066. Within industries and, to a lesser extent within regions, there is pronounced variation in the strength of agglomeration effects, and evidence of decreasing returns to agglomeration. High density areas attract firms that benefit most from agglomeration.

year: 2013

title: Lake Rotoiti fieldwork and modelling to support considerations of Ohau Channel diversion from Lake Rotoiti

authors: Hamilton, David P.

abstract: A detailed assessment of the water quality effects of the Ohau Channel inflow to Lake Rotoiti was carried out using field and computer modelling analyses. The modelling assessment evaluates the effects on Lake Rotoiti of partial (50%) or complete (100%) diversion of the Ohau Channel. A comprehensive bathymetric survey of Lake Rotoiti and the eastern end of Lake Rotorua was also carried out to provide information for the application of a three-dimensional model run by NIWA, so that different diversion wall positions and designs might be tested prior to possible implementation. Field measurements based on temperature, conductivity and chlorophyll fluorescence carried out from February to May 2004 captured instances when the Ohau Channel entered Lake Rotoiti as a buoyant overflow. These data and historical records suggest that approximately 20% of the buoyant surface inflow enters the main basin of Lake Rotoiti, while the remainder is short-circuited through the Kaituna arm to the outflow.

text: Lake Rotoiti fieldwork and modelling to support considerations of Ohau Channel diversion from Lake Rotoiti A detailed assessment of the water quality effects of the Ohau Channel inflow to Lake Rotoiti was carried out using field and computer modelling analyses. The modelling assessment evaluates the effects on Lake Rotoiti of partial (50%) or complete (100%) diversion of the Ohau Channel. A comprehensive bathymetric survey of Lake Rotoiti and the eastern end of Lake Rotorua was also carried out to provide information for the application of a three-dimensional model run by NIWA, so that different diversion wall positions and designs might be tested prior to possible implementation. Field measurements based on temperature, conductivity and chlorophyll fluorescence carried out from February to May 2004 captured instances when the Ohau Channel entered Lake Rotoiti as a buoyant overflow. These data and historical records suggest that approximately 20% of the buoyant surface inflow enters the main basin of Lake Rotoiti, while the remainder is short-circuited through the Kaituna arm to the outflow.

year: 2005-03

title: Science-practice roadshow 1: Summary perspectives from centralised entities and agencies

authors: Serrao-Neumann, Silvia

abstract: Flooding is Aotearoa-New Zealand’s most frequent natural hazard, regularly damaging buildings and infrastructure networks, and causing months of disruption to communities and businesses (Hutchings et al. 2019). Also, floods have indirect, cascading, and more intangible impacts (Lawrence, Blackett, and Cradock-Henry 2020), such as the withdrawal of future investment or the emotional stress of recovery. flood risk is predicted to rise quickly due to the combination of climate change and rapid urban intensification (Ministry for the Environment and The Flood Risk Management and River Control Review Steering Group 2008). 

Currently, there is no consistent approach to accurately determine flood risk on a national scale, nor how this may be changing as the climate warms. Instead, flooding risk assessments are done for individual catchments or locations, with the goal of managing and mitigating on the local scale. Local and regional governments vary widely in their capability and capacity to undertake this work (Ford, Berrang-Ford, and Berrang Ford 2011) and, thus, significant differences in data availability and modelling approaches mean that integration of results to gain a pan-region or nationwide picture has not been possible. 

The ‘Mā te haumaru ō nga puna wai ō Rākaihautū ka ora mo ake tonu: Increasing flood resilience across Aotearoa’ research develop a detailed nationwide model that could inform strategic and co-ordinated nationwide decision-making and regulations to support improved resilience to flood risk across the country. Utilising new methods and advances in computer processing and automation, the programme is developing a dynamic risk modelling framework that will assess flood hazard for every catchment in the country and under differing climate scenarios. The model will account for the risks to both built infrastructure and communities so that a fuller understanding of societal costs and impacts can be established. The model’s utility for supporting decision-making will be investigated using an initial set of scenarios for environmental planning, policy settings and infrastructure investment options. Two overarching themes across all of the research - Mtauranga Mori and Uncertainty – are designed to utilise the diverse knowledge systems available to develop tools that are relevant for communities throughout Aotearoa-New Zealand, and to take into account and communicate more clearly flood risks. 

Improved resilience to flooding across Aotearoa-New Zealand is a key outcome sought by the research programme, however it cannot be achieved by research alone. Instead, knowledge and information developed within the programme must be utilised by practitioners in their work to assist communities to plan for, manage, mitigate and avoid flood risks. New knowledge from the programme must be incorporated by practitioners into further tools, policy and decision-making frameworks. This knowledge translation however is not a straight forward process (Dilling and Lemos 2011). Cultural, behavioural and cognitive differences between those who produce and those who utilise knowledge mean that research outputs may not fit the requirements of their intended users, and thus, uptake of research outputs may be compromised. Conversely, strong engagement of knowledge users in the knowledge production process is known to increase the likelihood, and impact, of knowledge implementation. 

Stakeholders are key members of the programme’s research team, representing views across central and local government, engineering, planning consultancies, emergency management, insurance and banking industries, and Te Rūnanga o Wairewa (Banks Peninsula). To broaden the range of stakeholder perspectives, and to facilitate relationships across the programme, we have established a boundary organisation – Te W Te W . Boundary organisations (Guston 2001; Kirchhoff, Esselman, and Brown 2015) are forums that bridge between the two relatively different social worlds of knowledge producers (researchers/scientists) and users (practitioners/policy makers). These forums create and sustain legitimate space and collaboration for knowledge/information to be co-designed, co-produced and co-disseminated (Serrao-Neumann, Di Giulio, and Low Choy 2020). Within our programme, Te W Te W is responsible for organising and facilitating communication and collaboration activities – events (Science-Practice oadshows), communications channels such as an electronic newsletter and website, and learning opportunities. Through this organisation, we are fostering trust, legitimacy and capacity for information use so that our research results will be usable, useful, and used. 

This report summarises the discussion and perspectives shared at the first Science-Practice Roadshow held in October 2021.

text: Science-practice roadshow 1: Summary perspectives from centralised entities and agencies Flooding is Aotearoa-New Zealand’s most frequent natural hazard, regularly damaging buildings and infrastructure networks, and causing months of disruption to communities and businesses (Hutchings et al. 2019). Also, floods have indirect, cascading, and more intangible impacts (Lawrence, Blackett, and Cradock-Henry 2020), such as the withdrawal of future investment or the emotional stress of recovery. flood risk is predicted to rise quickly due to the combination of climate change and rapid urban intensification (Ministry for the Environment and The Flood Risk Management and River Control Review Steering Group 2008). 

Currently, there is no consistent approach to accurately determine flood risk on a national scale, nor how this may be changing as the climate warms. Instead, flooding risk assessments are done for individual catchments or locations, with the goal of managing and mitigating on the local scale. Local and regional governments vary widely in their capability and capacity to undertake this work (Ford, Berrang-Ford, and Berrang Ford 2011) and, thus, significant differences in data availability and modelling approaches mean that integration of results to gain a pan-region or nationwide picture has not been possible. 

The ‘Mā te haumaru ō nga puna wai ō Rākaihautū ka ora mo ake tonu: Increasing flood resilience across Aotearoa’ research develop a detailed nationwide model that could inform strategic and co-ordinated nationwide decision-making and regulations to support improved resilience to flood risk across the country. Utilising new methods and advances in computer processing and automation, the programme is developing a dynamic risk modelling framework that will assess flood hazard for every catchment in the country and under differing climate scenarios. The model will account for the risks to both built infrastructure and communities so that a fuller understanding of societal costs and impacts can be established. The model’s utility for supporting decision-making will be investigated using an initial set of scenarios for environmental planning, policy settings and infrastructure investment options. Two overarching themes across all of the research - Mtauranga Mori and Uncertainty – are designed to utilise the diverse knowledge systems available to develop tools that are relevant for communities throughout Aotearoa-New Zealand, and to take into account and communicate more clearly flood risks. 

Improved resilience to flooding across Aotearoa-New Zealand is a key outcome sought by the research programme, however it cannot be achieved by research alone. Instead, knowledge and information developed within the programme must be utilised by practitioners in their work to assist communities to plan for, manage, mitigate and avoid flood risks. New knowledge from the programme must be incorporated by practitioners into further tools, policy and decision-making frameworks. This knowledge translation however is not a straight forward process (Dilling and Lemos 2011). Cultural, behavioural and cognitive differences between those who produce and those who utilise knowledge mean that research outputs may not fit the requirements of their intended users, and thus, uptake of research outputs may be compromised. Conversely, strong engagement of knowledge users in the knowledge production process is known to increase the likelihood, and impact, of knowledge implementation. 

Stakeholders are key members of the programme’s research team, representing views across central and local government, engineering, planning consultancies, emergency management, insurance and banking industries, and Te Rūnanga o Wairewa (Banks Peninsula). To broaden the range of stakeholder perspectives, and to facilitate relationships across the programme, we have established a boundary organisation – Te W Te W . Boundary organisations (Guston 2001; Kirchhoff, Esselman, and Brown 2015) are forums that bridge between the two relatively different social worlds of knowledge producers (researchers/scientists) and users (practitioners/policy makers). These forums create and sustain legitimate space and collaboration for knowledge/information to be co-designed, co-produced and co-disseminated (Serrao-Neumann, Di Giulio, and Low Choy 2020). Within our programme, Te W Te W is responsible for organising and facilitating communication and collaboration activities – events (Science-Practice oadshows), communications channels such as an electronic newsletter and website, and learning opportunities. Through this organisation, we are fostering trust, legitimacy and capacity for information use so that our research results will be usable, useful, and used. 

This report summarises the discussion and perspectives shared at the first Science-Practice Roadshow held in October 2021.

year: 2022-02