# Multiple Choice Quizzes

Take the quiz test your understanding of the key concepts covered in the chapter. Try testing yourself before you read the chapter to see where your strengths and weaknesses are, then test yourself again once you’ve read the chapter to see how well you’ve understood.

1. What are panel data?

1. Data containing units measured at different time points
2. Data where each unit is measured at more than one time point
3. Data containing skewed variable distributions
4. Data measured at one point in time

b. Data where each unit is measured at more than one time point

2. What does it mean when we say that our panel is balanced?

1. When we have more time periods than units
2. When we have a large sample of units
3. When we have an equal number of time periods per unit
4. When we have an unequal number of time periods per unit

c. When we have an equal number of time periods per unit

3. Which model takes into account both the time-varying independent variables, the time-invariant independent variables and the unmeasured time-invariant variables?

1. Pooled OLS
2. Between effects
3. Fixed effects
4. Random effects

c. Fixed effects

4. How is the time-invariant independent variables and the unmeasured time-invariant variables captured in a fixed effects model?

1. By running an ordinary least squares regression.
2. By running an ordinary least squares regression with robust standard errors.
3. By taking the mean of each variable for each unit across time, and running a regression on the collapsed dataset of means.
4. By way of including unit dummy variables.

d. By way of including unit dummy variables.

5. What is the name of the statistical test that can help us determine whether to choose a fixed effects or a random effects model?

1. Hausman test
2. z-test
3. chi square test

a. Hausman test

6. Random effects is a weighted average between?

1. Pooled OLS and fixed effects
2. Pooled OLS and between effects
3. Between effects and fixed effects
4. Fixed effects and time fixed effects

c. Between effects and fixed effects

7. What characterizes time-series cross-section data?

1. When we have a large number of units recorded at few time points
2. When we have a small or medium sized number of units recorded at many time points
3. When we have a large number of units recorded at many time points
4. When we have a small or medium sized number of units recorded at few time points

b. When we have a small or medium sized number of units recorded at many time points

8. What does non-stationarity mean?

1. That parameters of our data (such as the mean and variance) do not change over time
2. That parameters of our data (such as the mean and variance) do change over time
3. When time series data are not influenced by their historical values
4. When time series data are influenced by their historical values

b. That parameters of our data (such as the mean and variance) do change over time

9. What does lagging variables mean?

1. That we use previous values of a variable
2. That we use future values of a variable
3. That we set all values at its mean across time
4. That we log transform the variable