Marketing 312 exam 2

A retailer records customer’s preferred delivery speed as: Standard, Express, Same Day. These categories indicate increasing delivery speed. What type of variable is this?

Ordinal

Two regression models are estimated using the same dependent variable and dataset.

Model A Model B

R² .71 .73

Adjusted R² .69 .68

Which model would generally be preferred if adjusted to R-squared is used for model selection?

Model A

A researcher observes monthly purchases from the same 500 households for 24 consecutive months. What type of dataset is this?

Panel data

A researcher has data on 1,000 customers observed only once. The dataset includes income, age, loyalty membership, and annual spending. Which question would be most difficult to answer using these data

Whether spending increases for the same customer after joining the loyalty program

A coffee company tests four package designs. Participants are randomly assigned to see one package and then report purchase intention, perceived quality, and brand trust.

The researcher first wants to determine whether average purchase intention differs across the four package designs. Which method is most appropriate?

ANOVA

A coffee company tests four package designs. Participants are randomly assigned to see one package and then report purchase intention, perceived quality, and brand trust.

The ANOVA produces a p-value of .03. What can the researcher conclude at the 5% significance level?

At least two group means differ

A coffee company tests four package designs. Participants are randomly assigned to see one package and then report purchase intention, perceived quality, and brand trust.

The researcher now wants to test whether the package designs differ jointly in purchase intention, perceived quality, and brand trust. Which method is most appropriate?

MANOVA

A restaurant chain observes weekly revenue at 120 restaurants for three years. Menu prices change over time. Restaurant size and neighborhood remain constant for each restaurant during the study period

Why might the researcher include restaurant fixed effects?

To control for characteristics of each restaurant that do not change over time

A restaurant chain observes weekly revenue at 120 restaurants for three years. Menu prices change over time. Restaurant size and neighborhood remain constant for each restaurant during the study period

If restaurant fixed effects are included, which variable cannot be separately estimated if it never changes during the sample period?

Restaurant size

A restaurant chain observes weekly revenue at 120 restaurants for three years. Menu prices change over time. Restaurant size and neighborhood remain constant for each restaurant during the study period

A nationwide holiday occurs during the same week for all restaurants and may affect revenue. What would best account for this common change?

Weekly fixed effects

What is the purpose of a t-test?

A t-test is a statistical method used to compare the average values in two groups

What is ANOVA?

ANOVA (Analysis of Variance) is a statistical method used to compare groups

Example of ANOVA

Research question: Does package design affect product liking?

• Independent variable (IV): Package design: Blue, Green, and Red

• Dependent variable (DV): Product liking (1–7 scale)

• Hypotheses:

• H₀: All group means are equal

• H₁: At least one group mean differs

What is MANOVA?

MANOVA (Multivariate Analysis of Variance) is a statistical method used to compare groups

Examples of MANOVA

• Research question: Does package design affect consumers’ evaluations?

• Independent variable (IV): Package design: Blue, Green, and Red

• Dependent variable (DV): Product liking, purchase intention, perceived quality (1–7 scale)

• Hypotheses:

• H₀: The mean values of the three DVs are the same across all groups

• H₁: At least one group differs in the mean of at least one DV

What is a Mediator?

An explanation on how or why x affects y

What are binary variables?

Represents membership for one category using a binary (0 or 1) value

What are nominal variables?

Similar to binary variables, but consist of more than two categories

Examples of nominal variables

• Brand: Apple, Samsung, Google

• Region: North, South, East, West

• Payment method: Cash, Credit Card, PayPal

What are Ordinal variables?

Similar to nominal variables, but the categories have a natural order

Example of ordinalvariables

• Education: High School, Bachelor's, Master’s

• Income: Low, Middle, High

What is Linear Regression

How to interpret the estimation results like a data analyst

Example of Linear Regression

𝑆𝑎𝑙𝑒𝑠𝑖 = 𝛽0 + 𝛽1 ∗ 𝑝𝑟𝑖𝑐𝑒𝑖 + 𝛽2 ∗ 𝑎𝑑𝑣𝑖 + 𝛽3 ∗ 𝑝𝑟𝑖𝑐𝑒𝑖 ∗ 𝑎𝑑𝑣𝑖 + 𝜀

What is Corss-Sectional data?

A dataset containing many observational units measured at a single point in time

Example of Cross-Sectional data

• 𝑃𝑢𝑟𝑐ℎ𝑎𝑠𝑒𝑖 = 𝛽0 + 𝛽1 ∗ 𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡𝑖 + 𝛽2 ∗ 𝐹𝑒𝑚𝑎𝑙𝑒𝑖 + 𝛽3 ∗ 𝑇𝑋𝑖 + 𝜀𝑖

• 𝑆𝑎𝑙𝑒𝑠𝑖 = 𝛽0 + 𝛽1 ∗ 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒𝑖 + 𝛽2 ∗ 𝑃𝑒𝑑𝑒𝑠𝑡𝑟𝑖𝑎𝑛𝑠𝑖 + 𝛽3 ∗ 𝐵𝑟𝑒𝑎𝑘𝑑𝑜𝑤𝑛𝑖 + 𝜀𝑖

• 𝑃𝑢𝑟𝑐ℎ𝑎𝑠𝑒𝑖 = 𝛽0 + 𝛽1 ∗ 𝑃𝑟𝑖𝑐𝑒𝑖 + 𝛽2 ∗ 𝑃𝑟𝑖𝑐𝑒𝑖 2 + 𝜀

What is Time-Series data?

Dataset containing repeated observations of the same observational unit over multiple points in time

What is Panel data?

Dataset containing multiple observational units measured

over multiple points in time

What is Difference-in-Differences (DiD/DD)

A classic method to compare treatment vs. control groups in natural experiments

Difference-in-Differences equation

𝑆𝑎𝑙𝑒𝑠𝑖𝑡 = 𝛽0 + 𝛽1 ∗ 𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡𝑖 + 𝛽2 ∗ 𝑃𝑜𝑠𝑡𝑡 + 𝛽3 ∗ 𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡𝑖 ∗ 𝑃𝑜𝑠𝑡𝑡 + 𝜀𝑖