The book first discusses in depth various aspects of the well-known inconsistency that arises when explanatory variables in a linear regression model are measured with error. Despite this inconsistency, the region where the true regression coeffecients lies can sometimes be characterized in a useful way, especially when bounds are known on the measurement error variance but also when such information is absent. Wage discrimination with imperfect productivity measurement is discussed as an important special case.

Next, it is shown that the inconsistency is not accidental but fundamental. Due to an identification problem, no consistent estimators may exist at all. Additional information is desirable. This information can be of various types. One type is exact prior knowledge about functions of the parameters. This leads to the CALS estimator. Another major type is in the form of instrumental variables. Many aspects of this are discussed, including heteroskedasticity, combination of data from different sources, construction of instruments from the available data, and the LIML estimator, which is especially relevant when the instruments are weak.

The scope is then widened to an embedding of the regression equation with measurement error in a multiple equations setting, leading to the exploratory factor analysis (EFA) model. This marks the step from measurement error to latent variables. Estimation of the EFA model leads to an eigenvalue problem. A variety of models is reviewed that involve eignevalue problems as their common characteristic.

EFA is extended to confirmatory factor analysis (CFA) by including restrictions on the parameters of the factor analysis model, and next by relating the factors to background variables.
These models are all structural equation models (SEMs), a very general and important class of models, with the LISREL model as its best-known representation, encompassing almost all linear equation systems with latent variables.

Estimation of SEMs can be viewed as an application of the generalized method of moments (GMM). GMM in general and for SEM in particular is discussed at great length, including the generality of GMM, optimal weighting, conditional moments, continuous updating, simulation estimation, the link with the method of maximum likelihood, and in particular testing and model evaluation for GMM.

The discussion concludes with nonlinear models. The emphasis is on polynomial models and models that are nonlinear due to a filter on the dependent variables, like discrete choice models or models with ordered categorical variables.

One of the Greatest Medical Mysteries of All Time "Relentless: The Search For Typhoid Mary" details the search for, the torment and the persecution of Mary Mallon - Typhoid Mary. It is the first book that gives her a voice and humanity. It shows why - of all the typhoid carriers in New York at the time - and there were hundreds - she alone was locked up for years in solitary confinement. It is a story as relevant today as it was in 1906. It deals with issues that fill today's nightly news; public health, immigration, class and economic warfare, the war on women, prejudice, injustice and the plight of minorities. What Readers Say: "I had trouble putting this book down. It presents the tale in the style of good historical fiction, though it is clearly based on fact, and it is an engaging read." - Jennifer Davis "This was one of the most exciting historical novels I've read in a long time... It reads very much like a mystery detective novel, with the clues and chase driving the plot." - Tienne McKenzie A story about the ground breaking investigation into the cause of typhoid - an epidemic killer of hundreds of thousands. In 1906, Dr. George Soper, of the New York Department of Health, was hired to investigate a single typhoid outbreak in Oyster Bay, New York. This investigation led him to identifying the cause of all the typhoid epidemics that had plagued the world throughout history. His investigation was thrilling and masterful. The key was the Irish cook, Mary Mallon; Typhoid Mary. Working with her employment agency, Soper discovered that she had left a trail of typhoid dating back six years. Typhoid Mary is still known as a medical villain, but is she? Or, is she a courageous, hard working, responsible person who had the misfortune of being an unattractive, unmarried woman and Irish immigrant at a time when, "Irish Need Not Apply" could be seen on signs advertising housing and jobs throughout the City? Was she persecuted for fighting for her rights? Or, was she simply a victim of New York's rich and powerful? If you like books like "The Hot Zone" pick up a copy today."