Question 1

The coefficients of selection bias correction models will automatically correct for any selection bias if the

Accepted Answer

By estimating the two equations jointly,the Heckman model automatically corrects for any bias.

Question 2

An example of a study-based selection bias is

Accepted Answer

The two types of study-based selection bias are file drawer effect and fishing (data mining).

Question 3

All of the following are data-based selection biases except

Accepted Answer

Unequal selection criteria is a participant-based selection criteria.

Question 4

In terms of ratings,which movies have the highest heterogeneity?

Accepted Answer

The standard deviation for the ratings is highest for Art (0.809)and Horror (0.905).

Question 5

It is rare that an overt selection bias will

Accepted Answer

An overt selection bias is extremely likely to have some type of effect on a study's results.

Question 6

_______________ occurs when researchers pre-screen potential participants on an outcome variable.

Accepted Answer

With unequal selection criteria,a researcher uses an outcome variable to determine who should participate in the study or in what capacity.

Question 7

_______________ is a data-based selection bias that occurs when data are deemed "bad" using arbitrary criteria,often as they come in,instead of using explicitly-stated or previously agree-upon standards.

Accepted Answer

With ad hoc rejection,the researcher decides arbitrarily that a piece of data looks bad and is,therefore,rejected.

Question 8

The model for selection in question #23 is used instead of others because

Accepted Answer

Because the binary probit model produces an error that is normally-distributed and easier to work with,it is used in the Heckman model.

Question 9

The following results from the Application Case Study presented in the text show means for selection of movies (Selection Distribution) and how they were rated (Prediction Distribution). Refer to this table to answer the following questions.
Hierarchical Bayes Sample Selection Model for Movie Ratings Predictions
 
-Which types of movies are not selected often,yet are rated highly when selected?

Accepted Answer

Classic movies have a selection mean of -2.070,but a rating mean of 1.375; Art movies have a selection mean of -0.523,but a rating mean of 1.462.

Question 10

In terms of selection,which two movies have the highest heterogeneity?

Accepted Answer

The standard deviation for the selection distribution is highest for Family (0.888)and Classic (1.118)movies.

Question 11

The most common type of selection bias correction model used by researchers is the

Accepted Answer

The Heckman model is the most frequently used selection bias correction model.

Question 12

The following results from the Application Case Study presented in the text show means for selection of movies (Selection Distribution) and how they were rated (Prediction Distribution). Refer to this table to answer the following questions.
Hierarchical Bayes Sample Selection Model for Movie Ratings Predictions
 
-Which type of movie is rated the highest?

Accepted Answer

Animation had a mean rating of 2.110,the highest.

Question 13

The following results from the Application Case Study presented in the text show means for selection of movies (Selection Distribution) and how they were rated (Prediction Distribution). Refer to this table to answer the following questions.
Hierarchical Bayes Sample Selection Model for Movie Ratings Predictions
 
-From the following list of movies,which one is rated the lowest?

Accepted Answer

Family was rated the lowest (-0.389 mean).

Question 14

The following results from the Application Case Study presented in the text show means for selection of movies (Selection Distribution) and how they were rated (Prediction Distribution). Refer to this table to answer the following questions.
Hierarchical Bayes Sample Selection Model for Movie Ratings Predictions
 
-Which gender is less likely to select a movie?

Accepted Answer

The -0.022 indicates males are slightly less likely to select a movie.

Question 15

Correcting for selection bias relies on the _______________ for selection

Accepted Answer

For the selection,the Heckman model uses the binary probit model because its normally-distributed error is somewhat easier to understand.

Question 16

Performing multiple,related studies and reporting only those that support the favored hypotheses is called

Accepted Answer

Reporting only a study that supports a favored hypothesis or repeating a study until the desired effects are obtained is called the file drawer effect.

Question 17

The following results from the Application Case Study presented in the text show means for selection of movies (Selection Distribution) and how they were rated (Prediction Distribution). Refer to this table to answer the following questions.
Hierarchical Bayes Sample Selection Model for Movie Ratings Predictions
 
-Which kind of movies are selected the least often?

Accepted Answer

Classic and Thriller have the highest negative means for selection.

Question 18

A hierarchical model that is estimated by Bayesian methods is called a

Accepted Answer

By definition,the hierarchical Bayes model is a hierarchical model that is estimated using a Bayesian method.

Question 19

The problem of selection bias was long been recognized by statisticians as a problem until the introduction of the

Accepted Answer

In 2000,James Heckman was awarded the Nobel Prize in Economics for his development of the Heckman model to deal with selection bias.

Question 20

All of the following are participant-based selection biases except

Accepted Answer

Premature termination is a data-based selection bias.

Quiz 12: Advanced Topics, research Frontiers, and Preparing the Final Report