9:017 moodle.concordia.ca 1. Omitted variable bias (OVB) occurs if the excluded variable is correlated with any of the included variables. im with over-fitting is imprecision. 2 of 3 )Xs, in the first step of both the forward and backward automatic search procedure, there are sions 4. If the confidence interval (CI) for the beta coefficient is (0.98, 1.17), one should fail to reject the null hypothesis Ho : e = 1. 5. A problem with the Linear Probability Model (LPM) is that B # [0, 1]. II. Problem - Use SAS for your computations. You have to show your work. No credit without an explanation (8 marks each). 1. We are interested in the factors explaining whether consumers make online purchases or not. A questionnaire was administered with a sample of 435 people. The data are in the file psl.sas7bdat in the 324_data folder. Here is the variables description: . Sex: 0=male, 1=female; . Age - in years; . Purchase: 1=online purchase made last year, 0=no online purchase made last year; Variables X1 to X34 are measured on a scale 1 to 7 where 1=strongly disagree and 7=strongly agree and are the answers to the question: "Indicate to what extent you agree with the following statements": I always purchase the types of products I want from the Internet There is a high risk for purchasing online Internet retailers encourage me to make suggestions The Internet retailers' websites provide in-depth information to answer my questions 5 I can buy the products that are not available in retail shops through the Internet 6 The website designs of the Internet retailers are aesthetically attractive Online shopping is not as secure as traditional retail shopping 9 I do not feel secure about providing my bank card details to a payment platform I have regular access to a computer 10 Internet shopping offers a wide variety of products 11 Online shopping offers better value for my money compared to traditional retail shopping 13 Family/friends encourage me to make purchases through the Internet Online shopping allows me to bay the same, or similar products, at cheaper prices than traditional retailing stores 14 It is easy to receive a personalized customer service from an Internet retailer 15 Online shopping allows me to save money as I do not need to pay transportation costs 16 It is quick and easy for me to complete a transaction through the website 17 It takes only a little time and effort to make a purchase through the Internet 18 I have knowledge about how to make purchases through the Internet 19 I have regular access to the Internet 20 Internet retailers offer good after sales service 21 Internet retailers understand my needs 22 I am very skilled at using the Internet 23 I am not confident that the information I provide to an Internet retailer is not used for other purposes 24 Internet retailers honour their product guarantees 25 I am not confident that my personal information is protected by an Internet retailer 26 The products I ordered are delivered to me within the time promised by the Internet retailers 27 The quantity and quality of the products I receive from Internet retailers are exactly the same as I order 29 Internet shopping saves me time, so I can do other activities The links within the website allow me to move back and forth easily between pages of the website 30 It is more convenient to shop through the Internet when compared to traditional retail shopping 31 Internet retailers' websites are easy to navigate 32 I think the Internet offers lower prices compared to retail stores 33 Marketing communication influence nced my decision to make purchases through the Internet 34 The media influenced my decision to make purchases through the Internet (a) Provide descriptive statistics for the variables "Sex", "Age" and "Purchase". (b) Present in a table the mean and standard deviation of each of the 34 variables X1-X34 ordered from the highest to the lowest value of the mean. Which of them seem the most important? (c) Present the means of the 34 Xs for women and men separately. Are there any differences? d) Do a Linear Probability Model (LPM) with the variable "Purchase" as a dependent variable and 36 independent variables - 34 Xs, "Sex" and "Age". Test them for statistical significance at 1% and interpret the ones that are. (e) Do a Logistic regression model (Logit) with the same variables as in (d). Test for statistical significance at 1% and interpret the coefficients that are. Are they different that the ones with the LPM? N