Denzil G Fiebig

• PhD
• Professor (Full) at UNSW Sydney

A basic prediction of theoretical models of insurance is that if consumers have private information about their risk of suffering a loss there will be a positive correlation between risk and the level of insurance coverage. We test this prediction in the context of the market for private health insurance in Australia. Despite a universal public sys...

The mixed or heterogeneous multinomial logit (MIXL) model has become popular in a number of fields, especially marketing, health economics, and industrial organization. In most applications of the model, the vector of consumer utility weights on product attributes is assumed to have a multivariate normal (MVN) distribution in the population. Thus,...

New contraceptive methods provide greater choice in terms of effectiveness, management of side-effects, convenience and frequency of administration and flexibility, but make the decisions about contraception more complex. There are limited data on the factors that determine women's choices among these alternatives, to inform providers about the fac...

While natural disasters cause loss of life and worsen health in the local areas they impact, the overall health impacts of these disasters can be more widespread. Using linked administrative and survey data (the 45 and Up Study) from Australia, a country where one in four residents was born overseas, we show that migrant mental health is significan...

To understand what Medicare aimed to achieve, we need to revisit the medico‐politics of the time, and the fear of the spectre of socialised medicine. That determined what could be changed (universal insurance and contributions according to means) and what could not (private medical service provision and fee‐for‐service). We consider what Medicare h...

This study examines the impact of social insurance benefit restrictions on physician behaviour, using ophthalmologists as a case study. We examine whether ophthalmologists use their market power to alter their fees and rebates across services to compensate for potential policy‐induced income losses. The results show that ophthalmologists substantia...

The use and costs of health care rise substantially in the months prior to death, and although the use of palliative care services may be expected to lead to less costly care, the evidence is mixed. We analysed the costs of care over the last year of life and the extent to which these are associated with the use and duration of specialist palliativ...

Private doctors and hospitals face incentives to intervene in the process of childbirth because they are employed and paid differently from their public counterparts. While private obstetric care has been associated with higher rates of caesarean birth, it is unclear to what extent this is attributable to unobserved selection effects related to cli...

We investigate how utilization of primary care, specialist care, and emergency department (ED) care (and the mix across the three) changes in response to a change in health need. We determine whether any changes in utilization are impacted by socio‐economic status. The use of a unique Australian data set that consists of a large survey linked to mu...

Birth centres offer a midwifery-led model of care which supports a non-medicalised approach to childbirth. They are often reported as having low rates of birth intervention, however the precise impact is obscured because less disadvantaged mothers with less complex pregnancies, and who prefer and often select little intervention, are more likely to...

This article investigates retirement decumulation behaviours using the Grouped Fixed-Effects (GFE) estimator applied to Australian panel data on drawdowns from phased withdrawal retirement income products. Behaviours exhibited by the distinct latent groups identified suggest that retirees may adopt simple heuristics determining how they draw down t...

The present study examines the reciprocal relationship between Internet use and cognitive function over time among middle-aged and older populations in China. We use data from the first three waves of the China Health and Retirement Longitudinal Study (CHARLS), where participants provided information on Internet use and cognitive function measures...

The paper considers the problem of estimating a multivariate probit model in a panel data setting with emphasis on sampling a high dimensional correlation matrix and improving the overall efficiency of the data augmentation approach. We reparameterize the correlation matrix in a principled way and then carry out efficient Bayesian inference by usin...

We examine the unregulated pricing behavior of physicians in response to an exogenous decrease in patient entitlements under a government scheme providing insurance for high out-of-pocket medical costs. We use survey-linked administrative data to estimate the causal effects of the policy change on consultation fees. Adopting a quasi-experimental di...

This article considers the problem of estimating a multivariate probit model in a panel data setting with emphasis on sampling a high-dimensional correlation matrix and improving the overall efficiency of the data augmentation approach. We reparameterise the correlation matrix in a principled way and then carry out efficient Bayesian inference usin...

OBJECTIVES: Scale heterogeneity, or differences in the error variance of choices, may account for a significant amount of the observed variation in the results of discrete choice experiments (DCEs) when comparing preferences between different groups of respondents. The aim of this study was to identify if, and how, scale heterogeneity has been addr...

The problem we consider considers estimating a multivariate longitudinal panel data model whose outcomes can be a combination of discrete and continuous variables. This problem is challenging because the likelihood is usually analytically intractable. Our article makes both a methodological contribution and also a substantive contribution to the ap...

We provide a user guide on the analysis of data (including best-worst and best-best data) generated from discrete-choice experiments (DCEs), comprising a theoretical review of the main choice models followed by practical advice on estimation and post-estimation. We also provide a review of standard software. In providing this guide, we endeavour to...

Within a generation, empirical researchers have experienced unprecedented increases in the availability of data. ‘Big data’ has arrived with considerable hype and a sense that these are dramatic shifts in the research environment that have wide-reaching implications across many disciplines. There is no doubt that the analysis of new and varied sour...

Micro panels characterized by large numbers of individuals observed over a short time period provide a rich source of information, but as yet there is only limited experience in using such data for forecasting. Existing simulation evidence supports the use of a fixed-effects approach when forecasting but it is not based on a truly micro panel set-u...

Decisions about prescribed contraception are typically the result of a consultation between a woman and her doctor. In order to better understand contraceptive choice within this environment, stated preference methods are utilized to ask doctors about what contraceptive options they would discuss with different types of women. The role of doctors i...

Despite concerns about reporting biases and interpretation, self-assessed health (SAH) remains the measure of health most used by researchers, in part reflecting its ease of collection and in part the observed correlation between SAH and objective measures of health. Using a unique Australian data set, which consists of survey data linked to admini...

The separate identification of effects due to incentives, selection and preference heterogeneity in insurance markets is the topic of much debate. In this paper, we investigate the presence and variation in moral hazard across health care procedures. The key motivating hypothesis is the expectation of larger causal effects in the case of more discr...

This paper estimates the impact of informal caregiving on self-reported well-being. It uses a sample of 23,285 respondents of the first eleven waves of the Household, Income and Labour Dynamics in Australia (HILDA). We apply a relatively new analytical method that enables us to estimate fixed effects ordered logit to analyse subjective well-being....

Explaining individual, regional, and provider variation in health care spending is of enormous value to policymakers but is often hampered by the lack of individual level detail in universal public health systems because budgeted spending is often not attributable to specific individuals. Even rarer is self-reported survey information that helps ex...

Objectives To determine how women and physicians rate individual characteristics of contraceptives. Methods Discrete choice experiments are used in health economics to elicit preferences for healthcare products. A choice experiment uses hypothetical scenarios to determine which individual factors influence choice. Women and general practitioners (G...

Background In the past decade, the range of contraceptives available has increased dramatically. There are limited data on the factors that determine women’s choices on contraceptive alternatives or what factors providers consider most important when recommending contraceptive products to women. Objectives Our objectives were to compare women’s (co...

Australia was one of the first countries to introduce a publicly funded Human Papilloma Virus (HPV) vaccine program, and its introduction coincided with a media campaign to promote regular cervical screening. One issue with HPV vaccination is how it impacts on demand for screening. This study examines changes in women's screening preferences follow...

This article presents a Bayesian analysis of a multinomial probit model by building on previous work that specified priors on identified parameters. The main contribution of our article is to propose a prior on the covariance matrix of the latent utilities that permits elements of the inverse of the covariance matrix to be identically zero. This al...

This study investigated the hypothesis that socioeconomic differences in health status change can largely be explained by the higher prevalence of individual health-risk behaviors among those of lower socioeconomic position. Data were from the Americans' Changing Lives study, a longitudinal survey of 3617 adults representative of the US non-institu...

Purpose: New contraceptive methods provide greater choice in terms of effectiveness, management of side-effects, convenience and frequency of administration and flexibility, but make the decisions about contraception more complex. There are limited data on the factors that determine women’s choices among these alternatives, to inform providers abou...

Contingent valuation models are used in Economics to value non-market goods and can be expressed as binary choice regression models with one of the regression coefficients fixed. A method for flexibly estimating the link function of such binary choice model is proposed by using a Dirichlet process mixture prior on the space of all latent variable...

Bayesian analysis is given of a random effects binary probit model that allows for heteroscedasticity. Real and simulated examples illustrate the approach and show that ignoring heteroscedasticity when it exists may lead to biased estimates and poor prediction. The computation is carried out by an efficient Markov chain Monte Carlo sampling scheme...

Despite the success internationally of cervical screening programs debate continues about optimal program design. This includes increasing participation rates among under-screened women, reducing unnecessary early re-screening, improving accuracy of and confidence in screening tests, and determining the cost-effectiveness of program parameters, suc...

Despite the success internationally of cervical screening programs debate continues about optimal program design. This includes increasing participation rates among under-screened women, reducing unnecessary early re-screening, improving accuracy of and confidence in screening tests, and determining the cost-effectiveness of program parameters, suc...

The vast majority of stated preference research in health economics has been conducted in the random utility model paradigm using discrete choice experiments (DCEs). Ryan and Gerard (2003) have reviewed the applications of DCEs in the field of health economics. We have updated this initial work to include studies published between 2001 and 2007. Fo...

Self-reported data collected via surveys are a key input into a wide range of research conducted by economists. It is well known that such data are subject to measurement error that arises when respondents are asked to recall past utilisation. Survey designers must determine the length of the recall period and face a trade-off as increasing the rec...

A Monte Carlo experiment is undertaken to examine the small sample properties of three alternative estimators of a bivariate probit model with selection. The three estimators are the censored probit estimator, single-equation probit applied to the selected sub-sample and single-equation probit applied to the full sample. These estimators are compar...

When consumers have private information about risk of suffering a loss, or equivalently, if insurers are prohibited from using observable information on risk in underwriting, theoretical models of insurance predict adverse selection. Yet the most common finding in empirical studies is that of no positive correlation between risk and insurance cover...

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The so-called "mixed" or "heterogeneous" multinomial logit (MIXL) model has become popular in a number of fields, especially Marketing, Health Economics and Industrial Organization. In most applications of the model, the vector of consumer utility weights on product attributes is assumed to have a multivariate normal (MVN) distribution in the popul...

Effective control of asthma requires regular preventive medication. Poor medication adherence suggests that patient preferences for medications may differ from the concerns of the prescribing clinicians. This study investigated patient preferences for preventive medications across symptom control, daily activities, medication side-effects, convenie...

This paper investigates the role of family formation in particular the effect of children - actual and desired - on the purchase of private health insurance. A unique panel data set of young Australian women (under 30 years old) from the Australian Longitudinal Study on Women's Health [ALSWH] is used and the model of insurance explicitly accounts f...

Long-term adherence to inhaled corticosteroids is poor despite the crucial role of preventer medications in achieving good asthma outcomes. This study was undertaken to explore patient preferences in relation to their current inhaled corticosteroid medication, a hypothetical preventer or no medication. A discrete choice experiment was conducted in...

Consumers can accumulate product information on the basis of a combination of searching, product advertising and expert advice. Examples of experts who provide product information include doctors advising patients on treatments, motor mechanics diagnosing car problems and recommending repairs, accountants recommending investment strategies, and plu...

This study explores factors that influence participation in genetic testing programs and the acceptance of multiple tests. Tay Sachs and cystic fibrosis are both genetically determined recessive disorders with differing severity, treatment availability, and prevalence in different population groups. We used a discrete choice experiment with a gener...

This study investigated the hypothesis that socioeconomic differences in health status change can largely be explained by the higher prevalence of individual health-risk behaviors among those of lower socioeconomic position. Data were from the Americans' Changing Lives study, a longitudinal survey of 3617 adults representative of the US non-institu...

The decision to undertake a screening test is conditional upon awareness of screening. From an econometric perspective there is a potential selection problem, if no distinction is made between aware and unaware non-screeners. This paper explores this problem through analysis of the determinants of cervical screening in Australia. Cervical cancer is...

We describe recent progress in several areas related to endogeneity, including: choice set formation and attention to attributes; interactions among decision-makers; respondents' strategic behavior in answering stated preference choices; models of multiple discrete/continuous choice; distributions of willingness-to-pay; and methods for handling tra...

Economists typically use and prefer to use market based data to model behaviour. Many of the health care choices that are of most interest to policy makers are about new interventions, for which there may be no market data. As a result, stated preference methods, including standard gamble, time-trade-off and contingent valuation have been commonly...

The main stumbling block in estimating credible empirical models of appliance purchase decisions is the lack of suitable data. Appliance choice studies typically merely identify the relationships between appliance stocks and current home occupiers, and have little value for understanding the decision-making processes actually involved in the purcha...

Using a sample of several hundred students we model progression in a first-year econometrics course. Our primary interest is in determining the usefulness of these models in the identification of 'students at risk'. This interest highlights the need to distinguish between students who drop the course and those who complete but who ultimately fail....

Despite the success internationally of cervical screening programs debate continues about optimal program design. This includes increasing participation rates among under-screened women, reducing unnecessary early re-screening, improving accuracy of and confidence in screening tests, and determining the cost-effectiveness of program parameters, suc...

This paper presents Bayesian methodology for the estimation of a bivariate probit model with an endogenous effect and both parametric linear and flexible semiparametric exogenous effects. The model is prompted by an analysis of the utilisation of health services in Australia using data from the Australian National Health Survey. The semiparametric...

Forecasting the diffusion of innovations in the telecommunications sector is a constantly recurring problem for national providers. The problem is characterised by short data series making the estimation of model parameters unreliable. However, the same innovation will be diffusing simultaneously in other national markets, although with a different...

It is not uncommon to observe the published forecasts of economic commentators closely bunched together over long periods of time. In our case, the phenomenon is observed for eight national panels of economists who report monthly forecasts. A framework is developed that conveniently nests within it several simple, yet plausible forecasting rules, a...

A large proportion of the world telecommunications market can be characterized as supply restricted. In ITU (1999) official waiting lists numbered about 50 million worldwide with an average waiting time of two years. More than 100 countries had not eliminated the waiting list for telephone connections and hence a supply restricted market prevailed...

The rapidly increasing use of outsourcing for IT services, both in the public and private sectors, has attracted much interest from researchers and practitioners alike. While early studies of IT outsourcing were largely qualitative in nature, more recent studies have attempted to analyse the outcomes achieved in quantitative terms. This paper is co...

The rapidly increasing use of outsourcing for IT services, both in the public and private sectors, has attracted much interest from researchers and practitioners alike. While early studies of IT outsourcing were largely qualitative in nature, more recent studies have attempted to analyse the outcomes achieved in quantitative terms. This paper is co...

Being able to disaggregate total energy demand into components attributable to specific end uses provides useful information and represents a primary input into any attempt to simulate the impact of policies aimed at encouraging households to use less energy or shift load. Conceptually the estimation problem can be solved by directly metering indiv...

There is a tendency for the true variability of feasible GLS estimators to be understated by asymptotic standard errors. For estimation of SUR models, this tendency becomes more severe in large equation systems when estimation of the error covariance matrix, C, becomes problematic. We explore a number of potential solutions involving the use of imp...

Data do not adhere to the usual statistical assumptions and applied work is made difficult by the need to cope with the myriad of problems that arise from flawed data. Prominent examples are data that contain missing values or where variables are only available in categorised form. Standard solutions include omitting incomplete records and replacin...

We discuss the standard linear regression model with nonspherical disturbances, where some regressors are annihilated by considering only the residuals from an auxiliary regression, and where, analogous to the Frisch-Waugh procedure, the original GLS procedure is applied to the transformed data. We call this procedure pseudo-GLS and give conditions...

In most electricity systems the residential sector is one of the main contributors to the system peak. This makes it important to know how different residential end uses, such as space heating or cooking, contribute to the system load curve at the time of system peak and also at other times of the day. In this paper we discuss the estimation of res...

The question of whether it is cheaper for households to use electricity or gas for space heating, water heating and cooking, generates much debate in Australia. Generally, gas appliances are technically less efficient than electrical appliances, but on a per MJ basis, gas is cheaper than electricity. The trade-off between these two factors has typi...

End-use energy models explain the demand for energy by households at the level of specific end uses, such as space heating, cooking and water heating. An important advantage of end-use energy models is their usefulness in analyzing complex policy questions relevant to understanding and managing the demand for energy. With data available on total ho...

We give a neccessary and sufficient condition for the equality of theOLS andGLS estimator of a subset of the regression coefficients in a linear model.

Eliminating negative end-use or appliance-consumption estimates and incorporating direct-metering information into the process of generating these estimates--these are two important aspects of conditional demand analysis that will be the focus of this paper. In both cases, a Bayesian approach seems a natural way of proceeding. What needs to be inve...

Casual observation suggests that the study of cointegration and the closely related topic of unit roots constitutes a considerable proportion of the current agenda for econometric research. I would like t o thank the guest editor of this special issue of Econometric Reviews for the opportunity to comment on this work.

Econometric analysis of the skew of price change distributions for an eighty industry sample over an eleven year period indicates that the distributions are less skewed in times of rapidly changing prices, in concentrated oligopolies, and in markets with little product heterogeneity. The results provide evidence of less price staggering and greater...

The primary aim of the paper is to place current methodological discussions in macroeconometric modeling contrasting the ‘theory first’ versus the ‘data first’ perspectives in the context of a broader methodological framework with a view to constructively appraise them. In particular, the paper focuses on Colander’s argument in his paper “Economist...

DELMOD is a domestic end-use forecasting and simulation model for the residential electricity load curve in New South Wales, Australia. For a given scenario it produces profiles for average working and non-working days for a given month. With its detailed representation of the appliance stock and socio-demographic characteristics, and its facilitie...

Joint estimation of the parameters of systems of multiple equations by Zellner’s (1962) method of seemingly unrelated regressions (SUR) will in general lead to efficiency gains relative to single equation estimation. The original work of Zellner (1962, 1963) and Zellner and Huang (1962) investigated the magnitude of these efficiency gains. In parti...

Recent contributions to the discussion about the conditions under which ordinary least squares in the seemingly unrelated regressions (SUR) model is the best linear unbiased estimator suggest a characterization of SUR models that is convenient for checking whether these conditions are satisfied. Standard pedagogic examples for SUR's, as well as mor...

This paper develops some extensions to the statistical approach to the estimation of residential end-use load curves and provides a substantive application of these developments to a sample of households. Importantly, the typical assumption that the coefficients of the appliance dummies are fixed, ignores two important sources of variation: during...

Conditional demand analysis (CDA) is a statistical method for allocating the total household electricity load during a period, into its constituent components, each associated with a particular electricity-using appliance or end-use. This is an indirect approach to the estimation of end-use demand and, quite naturally, it often generates imprecise...

The theoretical and empirical implications of omitted variables, particularly dynamic adjustment effects, are studied. In particular, the attempt to model for such omission by including possibly irrelevant variables is investigated. This extends the existing knowledge of misspecification analysis in several directions. Ordinary least squares is the...

The specification of dynamic models typically leads to the estimation of impact responses. A transformation that allows for the direct estimation of the implied long-run parameters is discussed and the problem of choosing an appropriate estimator is addressed. Because the standard estimators of long-run responses involve ratios of regression coeffi...

In this paper, we develop a four-parameter generalization of the logistic growth curve, the flexible-logistic (FLOG) model. It is shown that the FLOG model is sufficiently general to locate its point of inflection anywhere between its upper and lower bounds: it can offer wide variation in its degree of symmetry for a given point of inflection. Alth...

The demand for international telephone calls in Australia is comprised of three s ervices with three distinct prices. In order to estimate elasticities for both tariffs and surcharges, an econometric model is developed t hat has two submodels, each of which consists of an aggregate equatio n and an allocation system. One model determines how the to...

Some new evidence on the income own-price elasticities of demand for energy consumption by consumers is presented. Estimates are derived from a complete system of cross-country demand equations with energy being one of the commodities considered.

Measures are formulated for the dispersion of real income and relative prices across countries. They are applied to 30 countries in 1975 for 10 groups of consumer goods.