Zealand Household Research Articles

Quantifying age-specific household contacts in Aotearoa New Zealand for infectious disease modelling.

Accounting for population age structure and age-specific contact patterns is crucial for accurate modelling of human infectious disease dynamics and impact. A common approach is to use contact matrices, which estimate the number of contacts between individuals of different ages. These contact matrices are frequently based on data collected from populations with very different demographic and socio-economic characteristics from the population of interest. Here we use a comprehensive household composition dataset based on Aotearoa New Zealand census and administrative data to construct a household contact matrix and a synthetic population that can be used for modelling. We investigate the behaviour of a compartment-based and an agent-based epidemic model parametrized using these data, compared with a commonly used contact matrix that was constructed by projecting international data onto New Zealand's population. We find that using the New Zealand household data, either in a compartment-based model or in an agent-based model, leads to lower attack rates in older age groups compared with using the projected contact matrix. This difference becomes larger when household transmission is more dominant relative to non-household transmission. We provide electronic versions of the synthetic population and household contact matrix for other researchers to use in infectious disease models.

Long-term health conditions among household families in Aotearoa New Zealand: cross-sectional analysis of integrated Census and administrative data

aim: Little is known about the extent to which families in Aotearoa New Zealand are affected by long-term health conditions (HCs). This study aimed to explore the rates of nine selected HCs among New Zealand family members within the same household. method: Linked population and administrative health data were obtained for families living in the same household according to the 2013 New Zealand Census (N=1,043,172). Health data (2008–2013) were used to ascertain whether people in these families (N=3,137,517) received treatment or services for nine selected HCs: cancer, chronic obstructive pulmonary disease, heart disease, diabetes, dementia, gout, stroke, traumatic brain injury (TBI), or mental health/behaviour conditions (MHBCs). results: Over 60% of families included at least one person with a HC, and this rate was higher among multi-generation families (73.9%). The most common HCs were MHBCs (39.4% of families), diabetes (16.0%) and TBI (13.9%). At the highest level of socio-economic deprivation, 57.6% of children aged under 18 years lived with a family member who had a HC. conclusion: Three in five New Zealand household families included someone with at least one of nine selected HCs, with differences in the proportion affected according to family composition, socio-economic status and an individual’s ethnicity. This suggests that there are a substantial number of people at risk of the poor outcomes associated with the experience of HCs within their family.

Socioeconomic inequalities in greenhouse gas emissions from household travel in Aotearoa/New Zealand

BackgroundA just transition to a decarbonised transport system requires understanding current inequity in transport-related greenhouse gas emissions (GHGe). MethodsWe used the population-based nationally representative New Zealand Household Travel Survey (2015–2018 data) to examine inequalities in GHGe from household travel by NZDep (an area measure of socioeconomic position [SEP]). ResultsThere was a broadly linear association between SEP and GHGe from household travel. People resident in the least deprived areas emitted around 79 % more GHGe per week from household travel than those in the most [mean 63.6 CO2eq (95 %CI 58.5–68.6) compared to 35.6 kg CO2eq (95 %CI (32.6–38.6)]. Most of the difference was due to the additional 97 km per week travelled by car by people resident in the least deprived areas. Residents in the least deprived areas travelled further and more frequently for paid and unpaid work and leisure purposes than those in the most. Air travel also showed significant inequities with 2.4 % of residents in the least deprived areas reporting air travel in the last week compared to 0.1 % in the most deprived. Air travel was the second largest source of mean weekly transport emissions in residents living in the least deprived areas. ConclusionThere are large inequities by area deprivation in GHGe from household travel in Aotearoa/New Zealand. Transport policy needs to focus on measures to reduce emissions that are effective and reduce inequities. Significant work on policy processes, design and evaluation need to occur to facilitate this dual transformation.

Retirement Income and Financial Market Participation in New Zealand

Using New Zealand Household Economic Survey (HES) 2018 data, we examine the impact of direct financial market participation post-retirement on retirement income in New Zealand. Our results demonstrate the importance of post-retirement financial market participation in the enhancement of retirees’ financial well-being. We conclude that retirees who participate in the financial market enjoy a 78% increase in overall annuitised net wealth; further analysis also reveals a substantial 154% increase if government pensions are excluded from calculations of annuitised net wealth. Moreover, these retiree participants also show higher probabilities of financial-situation satisfaction. These results highlight the significant contribution to retirement income of direct financial market participation. Our paper sheds extra light on issues related to retirement financial well-being and has important implications for policy makers in New Zealand.

Travel inequities experienced by Pacific peoples in Aotearoa/New Zealand

Moving to a low carbon transport system represents an opportunity to create more equitable, as well as sustainable transport system. However, little is known about inequalities in transport by ethnicity. We examine current inequities in household travel between Pacific and non-Pacific populations in Aotearoa/NZ using the New Zealand Household Travel Survey (2003 to 2014). Participants were grouped into Pacific peoples if they identified with one or more Pacific ethnicities. Data were analysed for all of Aotearoa/NZ and for Auckland where two thirds of Pacific peoples live. Pacific peoples have less access to bicycles and cars and different patterns of travel compared to the non-Pacific population. Overall, Pacific peoples emit 30% less GHGe daily from household-level travel. These differences are likely due to differences in sociodemographic characteristics, physical, sociocultural and policy-regulatory environment by ethnicity. Transport policy needs to better recognise the distinct needs of Pacific peoples (and other underserved groups) and provide a low-carbon transport environment that supports their needs without increasing transport inequity.

The effect of super-sized passenger vehicles on walking and cycling

BACKGROUND AND AIM: Passenger vehicles are putting on weight world-wide. We aim to estimate the effects of this trend on the safety and attractiveness of walking and cycling in cities, focussing especially on the spectacular rise of the light truck (known as a double cab ute in New Zealand). METHODS: Review of relevant literature, analysis of secondary data sets including new vehicle sales, the New Zealand Household Travel Survey and manufacturer data sheets, police crash data, thematic analysis of advertising and product promotion, ad hoc roadside survey. RESULTS:Light truck and SUV sales are increasing rapidly in most countries. Mostly these vehicles are promoted for carrying, towing and exploring off road. Travel surveys show that in fact most trips are not work-related and do not require special towing and carrying capacity. On the whole these vehicles seldom go off-road but are commonly used in cities for car-like trips, with higher emissions of NOx and CO2. With increasing mass and power, injury rates amongst occupants are falling, but the risk to other road users may be increasing: a pedestrian struck at ≥50 kph by a ute or SUV in New Zealand is 2.3 times more likely to be fatally injured than if struck by a car. The most popular ute in New Zealand (the Ford Ranger) occupies 30% more road space than the most popular car, and therefore more commonly obstructs footpaths and bike lanes and leaves a smaller gap when passing on narrow city streets. CONCLUSIONS:Passenger vehicles in New Zealand and many other countries are super-sizing: increased pollution, greater injury risk, and domination of road space make it even more difficult to promote walking and cycling in cities. KEYWORDS: active transport, physical activity, injury

Beyond the bicycle: Seeing the context of the gender gap in cycling

BackgroundIn most countries women cycle less than men. This is despite the clear environmental and health benefits of active commuting. Feminist critiques suggest this gender gap reflects societal roles and values, yet there has been little empirical research on the differences in men's and women's cycling in the context of total travel. MethodsRegression analyses were used to explore the travel mode and distance travelled of 49 965 participants in the nationally representative, continuous, cross-sectional New Zealand Household Travel Survey (2002–2014). Regular cyclists were people who cycled at least 10 days in the preceding month. We reported results by gender and cyclist status. ResultsCar was the dominant mode of travel for all groups. While fewer women regularly cycled (2%) compared to men (5%), women travelled less each day (12–17% less distance) and were more likely to use public transport and walk than men. These gender patterns were broadly replicated in people who were regular cyclists. Women made 17–47% more motorised trips of less than 5 km than men each day. Overall half of regular cyclists achieved 600 METS or above per week through travel related physical activity, compared to 11–15% of non-regular cyclists. Even after full model adjustment men had more than twice the odds (OR 2.58 (95%CI:2.29–2.92)) of cycling compared to women. ConclusionsMen are more likely to cycle than women in NZ and cyclists get more physical activity. Nonetheless, analysis across all travel (irrespective of regularity of cycling status) suggests that women use more diverse travel modes and generate lower greenhouse gas emissions than men. Better consideration of the social processes shaping travel is needed to create policy, institutions, programmes and infrastructure that achieve the long term goals of the transport system, such as increasing cycling and reducing greenhouse gas emissions.

The close to home effect in road crashes

The notion that most crashes happen close to home has been repeated so often it has come to be an accepted truth. Despite this, to our knowledge there have not been any studies to date which have adequately accounted for rates of exposure in drawing conclusions concerning relative crash risk and distance from home. We addressed this gap by using data representative of all travel (from the New Zealand Household Travel Survey) and crashes in New Zealand, by New Zealand drivers, from 1 July 2013 to 30 June 2014. Trip origins, destinations and driver home address were used to convert 31,102 trips into travel exposure on roads at increasing distance from home. Travel data were compared with crash distance from home for 6,295 injury crashes involving 9,315 drivers. Analysis showed that on average, drivers were indeed more likely to crash close to home. Roads within 11km (6.8miles) of home accounted for half of all travel and 62% of all crashes. The ‘close to home’ effect held for male and female drivers. Novice (learner) drivers were the only demographic subgroup to not exhibit the close to home effect. Compared with crashes further away, crashes close to home were more likely to involve alcohol and diverted attention, and less likely to involve driver fatigue. These findings provide a mandate for continued investigation into the science of typical, everyday driving. We contend that behavioural effects associated with driving on familiar roads may be a factor in injury crash risk for experienced drivers.

The Influence of Urban Land-Use and Public Transport Facilities on Active Commuting in Wellington, New Zealand: Active Transport Forecasting Using the WILUTE Model

Physical activity has numerous physical and mental health benefits, and active commuting (walking or cycling to work) can help meet physical activity recommendations. This study investigated socioeconomic differences in active commuting, and assessed the impact of urban land-use and public transport policies on active commuting in the Wellington region in New Zealand. We combined data from the New Zealand Household Travel Survey and GIS data on land-use and public transport facilities with the Wellington Integrated Land-Use, Transportation and Environment (WILUTE) model, and forecasted changes in active commuter trips associated with changes in the built environment. Results indicated high income individuals were more likely to commute actively than individuals on low income. Several land-use and transportation factors were associated with active commuting and results from the modelling showed a potential increase in active commuting following an increase in bus frequency and parking fees. In conclusion, regional level policies stimulating environmental factors that directly or indirectly affect active commuting may be a promising strategy to increase population level physical activity. Access to, and frequency of, public transport in the neighbourhood can act as a facilitator for a more active lifestyle among its residents without negatively affecting disadvantaged groups.

The distributional impact of population ageing in New Zealand

This paper examines the potential distributional impacts of demographic change, particularly population ageing, and changes to labour force participation that are projected to arise over the next 50 years. The approach involves calibration weighting of the Treasury's microsimulation model, Taxwell, based on the New Zealand Household Economic Survey. The weights are adjusted for each projection year to ensure that a range of population aggregates (by age and gender) match the projected values provided by Statistics New Zealand. Measures of income inequality and poverty, along with the incidence of income tax, goods and services tax and a number of components of government spending (namely health and education) across age groups, are obtained. The results suggest that population ageing and expected changes in labour force participation, in isolation, do not have a significant impact on population-level measures of income inequality.

Gender differences in the mental health of single parents: New Zealand evidence from a household panel survey

In many countries single parents report poorer mental health than partnered parents. This study investigates whether there are gender differences in the mental health of single parents in New Zealand (and whether any gender difference varies with that among partnered parents), and examines key social and demographic mediators that may account for this difference. We used data on 905 single parents and 4,860 partnered parents from a New Zealand household panel survey that included the Kessler-10 measure of psychological distress. Linear regression analyses were used to investigate both interactions of gender and parental status, and confounding or mediation by other covariates. High/very high levels of psychological distress were reported by 15.7 % of single mothers and 9.1 % of single fathers, and 6.1 % of partnered mothers and 4.1 % of partnered fathers. In an Ordinary Least Squares regression of continuous K10 scores on gender, parental status and the interaction of both (plus adjustment for ethnicity, number of children and age), female single parents had a 1.46 higher K10 score than male single parents (95 % CI 0.48-2.44; 1.46). This difference was 0.98 (95 % CI -0.04 to 1.99) points greater than the gender difference among partnered parents. After controlling for further confounding or mediating covariates (educational level, labour force status and socioeconomic deprivation) both the gender difference among single parents (0.38, -0.56 to 1.31) and the interaction of gender and parental status (0.28 greater gender difference among single parents, -0.69 to 1.65) greatly reduced in magnitude and became non-significant, mainly due to adjustment for individual socioeconomic deprivation. The poorer mental health of single parents remains an important epidemiological phenomenon. Although research has produced mixed findings of the nature of gender differences in the mental health of single parents, our research adds to the increasing evidence that it is single mothers who have worse mental health. Our findings on the potential explanations of the gender difference in sole parent mental health suggest that socioeconomic deprivation is a key contributor.

Experimental investigation of geared domestic refrigerative dehumidifier performance in New Zealand household climates

Small refrigerative dehumidifiers, which are commonly used in New Zealand to reduce household moisture, typically operate in relatively cool environments, outside their optimum performance envelope. This study investigates the potential for improving the low-temperature dehumidification capacity of a domestic dehumidifier using an evaporator economiser, with particular emphasis on the limitations caused by evaporator frosting. The paper reports performance measurements on a modified domestic dehumidifier which can be operated either geared with an evaporator economiser, or ungeared. An empirical heat pump model, which was calibrated using the ungeared performance data, was also used to compare the two modes. The measured results show a clear improvement in the dehumidification capacity in the geared mode at the higher temperatures tested. The performance improvement in the lower temperature tests was less than that predicted by the model due to increased evaporator frosting under gearing and to limitations in the economiser model relating to latent cooling.

Acute Rheumatic Fever Associated With Household Crowding in a Developed Country

Acute rheumatic fever (ARF) and its sequelae, chronic rheumatic heart disease, remain important causes of morbidity and mortality worldwide, but there is little recent information about risk factors. The aim of this study was to examine the association between ARF and household crowding in New Zealand between 1996 and 2005. This ecologic study used hospitalization data and census data to calculate incidence rates by census area unit (CAU). Rates of ARF were examined in relation to individual factors (age, ethnicity) and area factors based on the CAU of home address (household crowding, New Zealand deprivation index, household income, and proportion of children aged 5-14 years). The multivariate relationship between ARF incidence and CAU-based variables was assessed using a zero-inflated negative binomial model. This study included 1249 new cases of ARF between 1996 and 2005. At the univariate level, ARF rates were associated with household crowding across all age groups and ethnicities. ARF rates were significantly and positively related to household crowding after controlling for age, ethnicity, household income, and the density of children in the neighborhood. The incidence rate ratio was 1.065 (95% confidence interval, 1.052-1.079) for the total population. In New Zealand, ARF rates are associated with household crowding at the CAU level. This finding supports action to reduce household crowding to improve health and reduce health inequalities. Our conclusion could be further investigated using a case-control study.

Who are minimum and sub‐minimum wage workers?

PurposeThe purpose of this paper is to provide a comprehensive portrait of who earns the minimum wage, in terms of the characteristics of the individual that are most important in determining this outcome.Design/methodology/approachThis study uses individual data from the Annual Income Supplements of the New Zealand (NZ) Household Labour Force Surveys between June 1997 and June 2004. This unit record data allows isolation of workers earning the minimum wage or close to it. A more sophisticated quantitative analysis is also carried out, where the probability of earning at or below the minimum wage is modelled to estimate what individual characteristics are most significant in determining minimum wage status.FindingsOne of the key findings was that individual characteristics (such as age) are much more important than household circumstance or industry affiliations, in terms of the probability of earning minimum wage.Originality/valueNZ has substantially increased minimum wages for teenagers and adults since 2000. For example, since the youth minimum was introduced in March 1994, it had increased by 52 per cent in real terms by 2004. Consequently, recent NZ experience offers a rare opportunity to isolate who earns the minimum wage and which subgroups are more likely to be potentially impacted by a rising minimum.

Warm homes: Drivers of the demand for heating in the residential sector in New Zealand

New Zealand houses are large, often poorly constructed and heated, by OECD standards, and consequently are colder and damper indoors than recommended by the World Health Organisation. This affects both the energy consumption and the health of households. The traditional New Zealand household pattern of only heating one room of the house has been unchanged for decades, although there has been substantial market penetration of unflued gas heaters and more recently heat pumps. This paper describes the residential sector and the results of two community-based trials of housing and heating interventions that have been designed to measure the impact of (1) retrofitting insulation and (2) replacing unflued gas heaters and electric resistance heaters with heat pumps, wood pellet burners and flued gas heaters. The paper describes findings on the rebound effect or ‘take-back’—the extent to which households take the gains from insulation and heating improvements as comfort (higher temperatures) rather than energy savings, and compares energy-saving patterns with those suggested by an earlier study. Findings on these aspects of household space heating are discussed in the context of the New Zealand government's policy drive for a more sustainable energy system, and the implications for climate change policy.

Estimating the number of New Zealand children with a physical disability

To estimate the number of New Zealand children who have a physical disability, and to describe this group in relation to sex, age, ethnic group and severity. We used data collected by Statistics New Zealand's Household Disability Survey 2001. Within the estimated 90 000 children aged 0-14 years with a disability as described in Disability Counts 2001, we identified a subgroup using information on the use of equipment suggestive of mobility disability, the numbers estimated to be in receipt of or in need of physiotherapy and/or occupational therapy, and the small number needing ramps or similar modifications. An estimated 14 500 children had a physical disability. This equates to an estimated 1.7% of the New Zealand population of children aged 0-14 years. Fifty-seven per cent were boys. An estimated 9600 were New Zealand-European, 3800 Maori and 600 Samoan. Approximately half were of moderate severity as defined by Statistics New Zealand. An estimated 9500 had a multiple disability. The rate is somewhat higher than in studies from countries where only locomotor disability is described, but similar to rates where other types of disability such as dexterity disability are included. This may reflect the fact that within our group are children who in other countries would have been described as having a dexterity or a self-help disability. It would be useful if future New Zealand data collection could attempt to separate these subgroups in order to allow better forward planning of health, education and family support services.

Minimum Wage Workers in New Zealand: Who are they?

The New Zealand minimum wage rate has recently experienced a sustained period of growth that looks set to continue under the current Labour-led government. Since 2002 the adult minimum wage rate has increased by 28% from $8 and hour to the current rate of $10.25. This rise in the minimum wage has outstripped average wages, which increased by 15% over the same period. This paper uses the New Zealand Household Labour Force Survey and its Income Supplement to identify minimum wage workers and describe their demographic and job characteristics. In particular, the paper examines changes in the characteristics of minimum wage workers between 2002 and 2005. Minimum wage workers, over this period, are relatively young (over a half are aged 16-25 years), predominantly female, working part-time and are likely to be employed in a Services and Sales related occupation and in the Retail and Hospitality industries. Between 2002 and 2005 there was a three-fold increase in the share of wage and salary workers identified as minimum wage workers. Minimum wage workers in 2005 were slightly older and more likely to be female, compared with 2002. In particular, the share of married females among minimum wage workers doubled and there was an increase in the share of minimum wage workers in the Health and Community Services industry sector.

Adult equivalence scales, inequality and poverty*

This paper examines the sensitivity of inequality and poverty measures to the adult equivalence scale and the unit of analysis. Comparisons are made using parametric equivalence scales, and income units include individuals, equivalent adults and households. The role of the correlation between equivalent income and household size, and the weight attached to children, is examined analytically. Empirical results are based on New Zealand Household Expenditure Survey (HES) data for total expenditure. Further results using a variety of equivalence scales, for New Zealand, Australia, the UK and the OECD, are examined.

Marginally Attached to the Labour Force

Since the beginning of the decade, the numbers of unemployed- who are usually regarded as a reserve labour force - have reached historically low levels, with a strong concomitant demand for labour. This has resulted in an increasing interest in issues pertaining to labour force participation.Using data from Statistics New Zealand's Household Labour Force Survey, this article explores the characteristics of those who are not in the labour force, but still have a marginal attachment to it. In times of low unemployment, this group may serve as an alternative source of potential labour supply, while in the longer run it may be drawn upon to increase the working-age population's participation in the labour force.

Youth Minimum Wage Reform and the Labour Market

This paper analyses the effects of a large reform in the minimum wages affecting youth workers in New Zealand since 2001. Prior to this reform, a youth minimum wage, applying to 16-19 year-olds, was set at 60% of the adult minimum. The reform had two components. First, it lowered the eligible age for the adult minimum wage from 20 to 18 years, and resulted in a 69 percent increase in the minimum wage for 18 and 19 year-olds. Second, the reform raised the youth minimum wage in two annual steps from 60% to 80% of the adult minimum, and resulted in a 41 percent increase in the minimum wage for 16 and 17 year-olds over a two-year period. We use data from the New Zealand Household Labour Force Survey (HLFS) to estimate the impact of these changes on a variety of labour market and related outcomes. We compare the average outcomes of these two groups of teenagers, before and after the policy reform, to those of 20-25 year-olds, who were unaffected by the reform. We find no robust evidence of adverse effects on youth employment or hours worked. In fact, we find stronger evidence of positive employment responses to the changes for both groups of teenagers, and that 16-17 year-olds increased their hours worked by 10-15 percent following the minimum wage changes. Given the absence of any adverse employment effects, we find significant increases in labour earnings and total income of teenagers relative to young adults. However, we do find some evidence of a decline in educational enrolment, and an increase in unemployment and inactivity, although these results depend on the specification adopted.