Indirect Estimation Techniques Research Articles

Time Trends in Social Class Mortality Differentials in the Netherlands, 1820-1920: An Assessment Based on Indirect Estimation Techniques

The question whether socioeconomic status gradients in adult mortality have changed over a broad historical period has become an important political and theoretical issue but is hard to test. In this article we study long-term trends in social inequality in adult mortality by using data for 2 (of the 11) provinces of the Netherlands for the period 1812–1922. We apply indirect estimation techniques, which have been developed for the analysis of mortality patterns in countries with deficient data. Our article shows that indeed there was a clear social class gradient in mortality, with the elite having higher survival chances between ages 35 and 55 than the middle class and farmers. Differences were even more apparent in comparison with workers. Over time there was a strong convergence among social classes in mortality levels. The implications of our results for the dominant views on the change in living standards in the past are discussed.

Time Trends in Social Class Mortality Differentials in the Netherlands, 1820–1920

The question whether socioeconomic status gradients in adult mortality have changed over a broad historical period has become an important political and theoretical issue but is hard to test. In this article we study long-term trends in social inequality in adult mortality by using data for 2 (of the 11) provinces of the Netherlands for the period 1812–1922. We apply indirect estimation techniques, which have been developed for the analysis of mortality patterns in countries with deficient data. Our article shows that indeed there was a clear social class gradient in mortality, with the elite having higher survival chances between ages 35 and 55 than the middle class and farmers. Differences were even more apparent in comparison with workers. Over time there was a strong convergence among social classes in mortality levels. The implications of our results for the dominant views on the change in living standards in the past are discussed.

Estimating the prevalence of individuals likely to use publicly funded alcohol treatment services: an indirect estimation technique

Determining prevalence estimates of illicit or stigmatized behaviours is problematic, due to under-reporting and difficulties in sampling adequately populations most at risk of engaging in such behaviours. This has led to the development of indirect prevalence estimation techniques such as multiplier methods, capture-recapture, multivariate indicator methods and back-calculation. This study reports on the development of a treatment multiplier to estimate the number of clients estimated to seek treatment through publicly funded services annually. This study uses a multiplier method of indirect prevalence estimation, using the number of clients receiving publicly funded treatment as the benchmark population. Data for the multiplier were collected through a drug and alcohol telephone information and referral helpline. Participants are callers seeking assistance for their own alcohol use. Results indicate that up to 40 200 individuals (95% confidence interval: 34 900, 47 000) may seek treatment at these agencies annually. This estimate represents a 300% increase in current publicly funded treatment provision. This method was cost-effective and resulted in estimates similar to those obtained through a population-based survey. This method can be adapted easily to areas with a complete registry of clients receiving publicly funded alcohol or drug treatment services and a helpline service with adequate geographic coverage.

What can we learn from indirect estimations on mortality in Mongolia, 1969-1989?

Abstract The closure of Mongolia to the international community during the 20th century resulted in a dearth of available data and analytic demographic studies. In the absence of mortality analysis during the socialist period, this paper proposes the use of indirect census-based techniques to estimate mortality levels and trends of the last two socialist decades (1969-1989). Due to census data quality and choice of model life table, results are not homogeneous. The respective effects of these two components are discussed in order to understand the results. However, despite these shortcomings, it is shown that during the last socialist decades in Mongolia, the health conditions of the population deteriorated. The Mongolian pattern is relatively similar to the situation documented for the ex-socialist republics. Causes of this similarity are discussed. (ProQuest: ... denotes text stops here in original.) 1. Introduction In 1921, the Mongol Ardyn Huv'sgalt Nam (MAHN) - the Mongolian People's Revolutionary Party - along with Soviet Russian support, proclaimed the independence of Mongolia from Chinese rule.2 In 1924, Mongolia adopted its first constitution instituting a People's Republic, becoming the first nation of the world (after the founders of the USSR (Russia, Ukraine, Belarus, and Transcaucasia)) to choose a socialist way of development. Since then, Mongolia's destiny has been closely linked to the USSR. Until 1991, its 70-years experience of socialist political and economic systems resulted in the closure of the country to the international community. The relative inaccessibility of demographic information and data resulted in a dearth of knowledge about demographic evolution during Mongolia's socialist period. However, in order to answer and foresee the needs of the centralized and planned economy, population has been considered a central variable by the successive socialist governments. The knowledge of national and regional population growth, population repartition by residence (urban-rural), and economic characteristics of population were prerequisites for the orientation of the Mongolian People Republic's development (Neupert 1996). During the past century, Mongolia conducted 9 population censuses: in 1918, 1935, 1944, 1956, 1963, 1969, 1979, 1989 and 2000. With the openness (il tod - Mongolian glasnost) and restructuration (iirchl i n baiguulalt - Mongolian perestroika) of the country during the 1980s,3 Mongolian demographic data have been more easily available, enabling demographic analysis of the socialist period. Surprisingly, the large amount of data collected by the National Statistical Office of Mongolia has been underused. In fact, as Neupert states (1996: 24), [s]tudies on the population dynamics of the country or on relationships between socio-economic and demographic variables have never been conducted. The huge amount of population data accumulated since the 1950s has never been used for any analytical purpose. Hence, the aim of this paper is to propose the use of population censuses to appraise through indirect estimation techniques, mortality levels and trends during the country's last decades of its socialist period. Among the few demographic studies on Mongolian socialist and post-socialist periods, mortality has not been a subject of intense attention. Studies conducted on mortality in Mongolia have focused exclusively on young age or maternal mortality, using mostly survey data (for early-age, Dashtseren 2002, Neupert 1995, Pandey 1997; for maternal mortality, Janes and Chuluundorj 2004). In fact, little is known about general mortality levels and trends in Mongolia, both during and after the socialist era. Usually, in international comparisons, Mongolia - which is included in East Asia according to convention - is never taken into account due to lack of reliable detailed information (Zhao and Kinfu 2005). After introducing national population censuses in the past century, demographic analysis is employed to evaluate their quality. …

The mortality impact of the August 2003 heat wave in France: Investigating the ‘harvesting’ effect and other long-term consequences

In August 2003, Western Europe experienced a deadly heat wave. It is estimated that 15,000 people died in France from its direct effects. Applying an indirect estimation technique to the monthly number of deaths by sex, age, and place of residence for the period 1996–2003, we estimate the number of years that would have remained to those who died from the heat wave had they been spared. The paper also evaluates the role of the ‘harvesting’ effect of the 2003 heat wave in explaining the deficit of deaths recorded in 2004—estimated at 23,000 out of an expected total of 535,000 deaths. The harvesting effect was modest and accounted for fewer than 5,000 of the ‘missing’ deaths in 2004. The mortality decline in 2004 is thus due mainly to other factors. One hypothesis is that special efforts have been directed towards isolated older people as a consequence of the heat wave.

Induced Abortion and Unintended Pregnancy In Guatemala

Although Guatemalan law permits induced abortion only to save a woman's life, many women obtain abortions, often under unsafe conditions and in response to an unintended pregnancy. Recent studies indicate that unsafe abortion is a key factor contributing to maternal morbidity and mortality in the country, but no national data on the incidence of abortion exist. Surveys of all hospitals that treat women for postabortion complications and of 74 professionals who are knowledgeable about the conditions of abortion provision in Guatemala were conducted in 2003. Indirect estimation techniques were used to calculate the number of induced abortions performed annually. Abortion rates and ratios and the level of unintended pregnancy were calculated for the nation and its eight regions. Nearly 65,000 induced abortions are performed annually in Guatemala, and about 21,600 women are hospitalized for treatment of complications. Abortions occur at a rate of 24 per 1,000 women aged 15-49, and there is one abortion for every six births. The abortion rate is higher than average in the Southwest (less developed, mainly indigenous population) and Metropolitan (more developed, mainly nonindigenous population) regions (29-30 per 1,000 women). Over a quarter of all births are unplanned; combining unplanned births with abortions yields estimates that 32% of pregnancies in Guatemala are unintended, with an unintended pregnancy rate of 66 per 1,000 women. Unsafe abortion has a significant impact on women's health in Guatemala. Comprehensive government programs are needed to address the issues of unintended pregnancy and unsafe abortion, with attention to regional differences.

Frequency Response of Oil Impregnated Pressboard and Paper Samples for Estimating Moisture in Transformer Insulation

Knowledge about moisture content in oil impregnated paper insulation is essential when estimating remaining lifetime of power transformers. Direct evaluation of moisture content is rarely possible due to inaccessibility of the internal insulation system in transformers. Therefore, various indirect estimation techniques are utilized. Frequency domain spectroscopy (FDS) measurements of transformer insulation belong to this group. To perform high quality interpretation of results of FDS measurements a good knowledge on dielectric responses in oil impregnated pressboard and paper is required, especially as it refers to their variation with water content and temperature. The aim of this paper is to provide an open access to the frequency domain spectra of oil impregnated paper and pressboard samples, which can then be used in modeling of the results of diagnostic measurements in power transformers.

The Incidence of Induced Abortion in Uganda

Although Uganda's law permits induced abortion only to save a woman's life, many women obtain abortions, often under unhygienic conditions. Small-scale studies suggest that unsafe abortion is an important health problem in Uganda, but no national quantitative studies of abortion exist. A nationally representative survey of 313 health facilities that treat women who have postabortion complications and a survey of 53 professionals who are knowledgeable about the conditions of abortion provision in Uganda were conducted in 2003. Indirect estimation techniques were applied to the data to calculate the number of induced abortions performed annually. Abortion rates, abortion ratios and unintended pregnancy rates were calculated for the nation and its four major regions. Data on contraceptive use and unmet need were obtained from Demographic and Health Surveys. Each year, an estimated 297,000 induced abortions are performed in Uganda, and nearly 85,000 women are treated for complications. Abortions occur at a rate of 54 per 1,000 women aged 15-49 and account for one in five pregnancies. The abortion rate is higher than average in the Central region (62 per 1,000 women), the country's most urban and economically developed region. It is also very high in the Northern region (70 per 1,000). Nationally, about half of pregnancies are unintended; 51% of married women aged 15-49 and 12% of their unmarried counterparts have an unmet need for effective contraceptives. Unsafe abortion exacts a heavy toll on women in Uganda. To reduce unplanned pregnancy and unsafe abortion, and to improve women's health, increased access to contraceptive services is needed for all women.

Determinants of the Informal Economy: The Importance of Regional Factors

This paper analyses the determinants of the size of the informal economy using crosscountry regressions. Two sets of global data using indirect estimation techniques and the perception of business leaders for 109 countries as well as a regional set for Latin America based on direct data are used to estimate the size of the informal economies. Indirect estimation techniques arrive at higher estimates of the size of the informal economy than the perceptions of business leaders because they include not only the (fundamentally legal) activities of the informal sector, but also those activities which are illegal per se. Both kinds of estimate show strong regional differences in the size of the informal economies. Regressions on a set of indicators covering the intensity of regulations, taxes and the cost of establishing a business reveal that the intensity of labour regulations seems to be the most important factor in explaining the size of the informal economy in cross-country regressions using the rational behaviour approach. Socio-cultural indicators are only important in explaining the size of the informal economies in Latin America. Government efficiency is an important factor in explaining the size of the informal economy in world regressions. Regional regressions reveal that different aspects of governance dominate the relationship between government efficiency and the size of the informal economy in the different regions. Governments that seek to limit or decrease the size of the informal economy must therefore start from a country-specific analysis of the reasons why economic agents choose to conduct their business in the informal sector.

Discontinuities in indirect estimation: An application to EAR models

Among the simulation-based methods, indirect estimation techniques like Indirect Inference (I NDI NF) and Efficient Method of Moments (E MM) provide a simple solution to many computational problems associated with intractable Likelihood functions. Optimisation of the objective function can be critical in presence of not continuous response variables like, for instance, binary choice or discrete choice models, limited dependent variables, switching regime models. In particular, gradient-based optimisation algorithms can face difficulties when the not continuous response involves discontinuities in the objective function. A simple computational tool is suggested to “empirically” solve the problem. The case study is E MM applied to the autoregressive model with exponential marginal distribution (E AR). The proposed solution is also compared with the performance of the Conditional Least Squares estimation, suitable for this autoregressive model, by a set of Monte Carlo experiments.

Measurement of particle phase dry deposition fluxes of polychlorinated biphenyls (PCBs) with a water surface sampler

Abstract It has been shown that the atmospheric pathways including dry deposition are an important source of polychlorinated biphenyls (PCBs) entering surface waters in many locations. To assess how important this pathway is, accurate measurements or modeled estimates of dry deposition are needed. However, dry deposition is not well quantified because the direct measurement of dry deposition is difficult and indirect estimation techniques have substantial uncertainties associated with them. In this study, PCB dry deposition fluxes were directly measured with a water surface sampler (WSS) simultaneously with measurements of airborne concentrations in the Chicago urban area. The average particulate phase PCB flux to the WSS was 240±160 ng/m 2 -d, and the particulate phase airborne concentrations was 0.08±0.05 ng/m 3 . Average overall dry deposition velocities, calculated by dividing the fluxes by total particle phase PCB concentrations were 4.2±2.7 cm/s. This number is consistent with values determined using similar experimental techniques and higher than the values typically used to model PCB dry deposition. This difference may be due, in part, to the influence of PCBs associated with large particles being deposited onto the WSS.

Statistical issues in reporting quality data: small samples and casemix variation.

To present two key statistical issues that arise in analysis and reporting of quality data. Casemix variation is relevant to quality reporting when the units being measured have differing distributions of patient characteristics that also affect the quality outcome. When this is the case, adjustment using stratification or regression may be appropriate. Such adjustments may be controversial when the patient characteristic does not have an obvious relationship to the outcome. Stratified reporting poses problems for sample size and reporting format, but may be useful when casemix effects vary across units. Although there are no absolute standards of reliability, high reliabilities (interunit F > or = 10 or reliability > or = 0.9) are desirable for distinguishing above- and below-average units. When small or unequal sample sizes complicate reporting, precision may be improved using indirect estimation techniques that incorporate auxiliary information, and 'shrinkage' estimation can help to summarize the strength of evidence about units with small samples. With broader understanding of casemix adjustment and methods for analyzing small samples, quality data can be analysed and reported more accurately.

A hybrid feedforward neural network model for the cephalosporin C production process

At present, direct on-line measurements of key bioprocess variables as biomass, substrate and product concentrations is a difficult task. Many of the available hardware sensors are either expensive or lack reliability and robustness. To overcome this problem, indirect estimation techniques have been studied during the last decade. Inference algorithms rely either on phenomenological or on empirical models. Recently, hybrid models that combine these two approaches have received great attention. In this work, a hybrid neural network algorithm was applied to a fermentative process. Mass balance equations were coupled to a feedforward neural network (FNN). The FNN was used to estimate cellular growth and product formation rates, which are inserted into the mass balance equations. On-line data of cephalosporin C fed-batch fermentation were used. The measured variables employed by the inference algorithm were the contents of CO2 and O2 in the effluent gas. The fairly good results obtained encourage further studies to use this approach in the development of process control algorithms.

Disaggregating the historical demographic sources of regional foreign-born and native-born population growth in the United States: a new method with applications

In this paper we offer a general method for analysing the demographic processes that contribute to population growth and redistribution in a multiregional system. The method incorporates a historical perspective that can be used to trace dynamic population processes as they evolve over time. It uses an open multiregional projection model framework for identifying the contributions to regional growth made by each of the principal demographic components of change: fertility, mortality, immigration, emigration, in-migration and out-migration. At the same time, the method recognises the importance of disaggregating the native-born and foreign-born populations. Available public data and indirect estimation techniques are used to develop the data inputs for the projection model, with which we reconstruct the regional population changes for each five-year period between 1950 and 1990. Regional growth rates for the foreign-born and native-born populations are partitioned into the separate demographic components of change, and the projection model identifies the separate contributions to regional growth made by each population. This allows a direct comparison of the impacts of immigration with those of corresponding native-born contributions effected through internal migration and natural increases. Finally, application of the method allows us to identify the contribution that ‘recent’ (post-1965) immigrant cohorts have made to the composition of the youngest age groups in each region, and also to simulate the impacts of zero immigration scenarios on regional growth. Copyright © 1999 John Wiley & Sons, Ltd.

Disaggregating the historical demographic sources of regional foreign-born and native-born population growth in the United States: a new method with applications.

In this paper we offer a general method for analysing the demographic processes that contribute to population growth and redistribution in a multiregional system. The method incorporates a historical perspective that can be used to trace dynamic population processes as they evolve over time. It uses an open multiregional projection model framework for identifying the contributions to regional growth made by each of the principal demographic components of change: fertility, mortality, immigration, emigration, in-migration and out-migration. At the same time, the method recognises the importance of disaggregating the native-born and foreign-born populations. Available public data and indirect estimation techniques are used to develop the data inputs for the projection model, with which we reconstruct the regional population changes for each five-year period between 1950 and 1990. Regional growth rates for the foreign-born and native-born populations are partitioned into the separate demographic components of change, and the projection model identifies the separate contributions to regional growth made by each population. This allows a direct comparison of the impacts of immigration with those of corresponding native-born contributions effected through internal migration and natural increases. Finally, application of the method allows us to identify the contribution that ‘recent’ (post-1965) immigrant cohorts have made to the composition of the youngest age groups in each region, and also to simulate the impacts of zero immigration scenarios on regional growth. Copyright © 1999 John Wiley & Sons, Ltd.

An In-situ Identification Method for Joint Parameters in Mechanical Structures

This paper presents an improved scheme based on the frequency response functions (FRFs) for in-situ identification of joint parameters of mechanical structures. Despite that measurement of FRFs at joint locations is essential for identifying the joint parameters of a structural dynamic system, it is often impossible to measure FRFs at joint locations. To this end, the present paper suggests an indirect estimation technique for unmeasured FRFs which are required for identification but not available. Theoretical investigation is made to delineate the effects of measurement noise and modeling error on indirect estimation and identification. Two index functions are introduced, which can indicate the quality of estimation or identification along the frequency. The index functions are proven to be useful not only as a weighting function in the identification procedure but also for evaluating the frequency region appropriate for identification. A series of simulations as well as experiments are performed for validation of the method.

Direct comparison of four different biomass estimation techniques against conventional dry weight measurements

Many indirect biomass estimation techniques have been discussed in the literature; however, a comparison of the applicability of these methods for bioprocess control purposes has not been discussed comprehensively. In this paper, four different uncomplicated biomass measurement techniques were directly compared with the conventional biomass dry weight measurement, and the possibilities of their implementation in process control environments is discussed. These techniques are estimations based on laser turbidimeter signals, measurement of cell numbers and sizes, estimations based on the oxygen mass balance, and, finally, estimations based on the base consumption during pH control. All these techniques led to essentially the same quality of estimations. The comparisons were performed in experiments with two bacteria strains. Cross-validation analyses showed that all measurements are sufficiently accurate for process supervision and control purposes. The final decision about implementation of one of the techniques discussed must be made under consideration of the available equipment, the microorganisms to be cultivated and the cultivation conditions.

Experimental Identification of Dynamic Parameters of Rolling Element Bearings in Machine Tools

In-situ identification is essential for estimating bearing joint parameters involved in spindle systems because of the inherent interaction between the bearings and spindle. This paper presents in-situ identification results for rolling element bearing parameters involved in machine tools by using frequency response functions (FRF’s). An indirect estimation technique is used for the estimation of unmeasured FRF’s, which are required for identification of joint parameters but are not available. With the help of an index function, which is devised for indicating the quality of estimation or identification at a particular frequency, the frequency region appropriate for identification is selected. Experiments are conducted on two different machine tool spindles. Repeatable and accurate joint coefficients are obtained for both machine tool systems. [S0022-0434(00)02501-6]

ESTIMATION OF BODY MASS IN THE SOUTHERN ELEPHANT SEAL, MIROUNGA LEONINA, BY PHOTOGRAMMETRY AND MORPHOMETRICS

AbstractA simple photographic technique was developed to indirectly estimate body mass data for southern elephant seal (Mirounga leonina) cows (postlactation), yearlings, and immature males and females. Regressions of mass on both photographic and morphometric variables (together and separately) yielded useful, predictable models. Using such variables, the best estimation of the actual mass was for postlactation cows, with a 95% confidence interval of ± 2.66% of the predicted body mass. Although combining photographic and morphometric variables produced the most reliable models specifically for cows and yearlings, the most practical model contained only the morphometric variables length and girth squared. Side area was the best correlated single photographic variable and this corresponded with other studies. Photogrammetry could be useful when animals cannot be sedated and are located on a flat surface, but it does require animals to be motionless when approached. Thus, the procedure may be more suited to bulls rather than other age classes and could have a role in studies where large numbers of mass estimations are rapidly required. If sedation is utilized in smaller animals, then the use of body length and girth is the most suitable indirect mass estimation technique to avoid the use of heavy weighing equipment.

A Note on Remarriage Reporting in the 1910 U.S. Census

The quality of remarriage reporting among native-born whites in the 1910 United States Census is assessed using indirect demographic estimation techniques and vital statistics on divorce. Specifically, I compare the reports of remarriage in the census with estimates based on the extent of widowhood and divorce. After adjusting for possible levels of underreporting of divorce in the census, I estimate that the reports of remarriage among native- born whites in the 1910 census are underreported by less than 5 percent through age 49. At older ages, however, the underreporting rises to 9 percent among women and up to 21 percent among men. In the process of validating the remarriage reports in the census, I calculate the proportion of the divorced and widowed population who remarry, information that is not available directly from the census. These estimates can be used as a baseline for studies of remarriage in the U.S. in the twentieth century.