Econ - 1039 Words

Preface In our data analysis we do some univariate analysis before proceeding to models. In survival analysis it is highly recommended to look at the Kaplan-Meier curves for all the categorical predictors. This will provide insight into the shape of the survival function for each group and give an idea of whether or not the groups are proportional. We also consider the tests of equality across strata to explore whether or not to include the predictor in the final model. For the categorical variables such as marital, eservice, plusservice and totalservice we use the log-rank test of equality across strata which is a non-parametric test. For the continuous variables such as age, address, income, education, employment, and reside we use a†¦show more content†¦Consequently we find the better model after dropping variables with the p-values more than 0.05. Model 5 is the best model which has all the significant variables and has lowest AIC value of 1478.82 and BIC value of 1513.17. If the marital status is altered from married to unmarried, while holding all other variables constant, the rate of churn decreases by (100% - 66.5%) = 33.5%. As year in current address is increased by one year, all other variables are held constant, the rate of churn decreases by (100% - 94.5%) = 5.5%. As year with current employer is increased by one year, all other variables are held constant, the rate of churn decreases by (100% - 93.2%) = 6.8%. As people switch from non eservice to e service, all other variables are held constant, the churn rate decrease by (100% - 56.5%) = 43.5%. As people switch from non plusservice to plusservice, all other variables are held constant, the churn rate decrease by (100% - 54.5%) = 45.5%. As education level increases, all other variables are held constant, the churn rate increases by 12.83%. Finally, I adjust my model for heteroscedasticity by using robust function. The final adjusted model is presented below: Table 1: Final Model (Corrected for Heteroscedasticity) |Variable |Haz. Ratio |Robust Standard Error |Z-value |Significant | |marital |0.665 |.0790557 |-3.43 |** |Show MoreRelatedEcon984 Words   |  4 PagesMaximum four per group, all students must be registered in the same section of the same course. Names must be in alphabetical order on the cover page. †¢ Graded work will be available for pick-up beginning on the afternoon of Friday March 14 in the Econ Distribution Center, Dunning Hall Room 334. You will require your student card. †¢ This assignment covers material from Chapters 20-24 of the text. True, False, or Uncertain [48 marks - 6 marks each] Explain why each of the followingRead MoreEcon1249 Words   |  5 PagesECON 410.502 Macroeconomic Theory Spring 2010 Instructor: Guangyi Ma Extra Problems #1 Suggested Answers and Comments Notice: (1) This set of extra problems contains 25 multiple-choice problems and 6 analytic (short-answer) problems. These problems are not homework and will not be graded. The aim of these problems is to provide you with additional exercises. (2) I will give solutions of the assignment and the â€Å"extra-problem† set after the due date. Page 1 Problem 1~25: MultipleRead MoreEcon Ans975 Words   |  4 PagesECON2103 – Problem Set (1) Multiple Choice Questions: 1. Understanding opportunity cost You work as an assistant coach on the university basketball team and earn $12 per hour. One day, you decide to skip the hour-long practice and go to the local carnival instead, which has an admission fee of $7. 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Increase [Q#2057] At any moment the equilibrium price in the market for tablet computers will be determined by ________ . c. Buyers and the sellers of tablet computers [Q#2059] The equilibrium price is also known as c. the market-clearing price. [Q#4021] Along a demand curve with a constant slopeRead MoreEcon4429 Words   |  18 PagesECON 11026 Assignment Item 1 . S0183732 Part A Q1ai) Article can be found in the following website : http://www.skynews.com.au/businessnews/article.aspx?id=738928amp;vId= The article ‘ Strong jobs figures put rate cut in doubt’ described that there is an increase in employment in the last one month which might help in putting hold to rate cut by Reserve Bank of Australia. There are positive signs in Australian job market with increase in 44000 employed peopleRead MoreEcon754 Words   |  4 PagesAssume that a cargo ship carrying the merchandise of a cloth merchant has been wrecked. 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Your Answer(s): * 5000 Correct Answer(s) (in green): * 5000 * 3500 * 1000 * 500 Question 2: In the Private Sector, there are many  choices  to be made by Business managers regarding which â€Å"projects† to borrow for and which â€Å"projects† to invest in.  Ã‚  These choices often contain a great deal of ______________________  as well as  the potential for benefitsRead MoreEcon1239 Words   |  5 PagesQuestions based on â€Å"Too Big to Fail† movie Watch the movie and answer the following questions briefly. Upload your answers on Moodle using the Link â€Å"Submit Assignment on Too Big to Fail here† 1. When Lehman brothers was in trouble, Henry Paulson called the other banks’ CEOs on a meeting to find a solution to Lehman Brothers’s problem? Why did Henry Paulson think that a private sector solution, instead of government bailout, was needed? 2. (Up to about 43:00 of the movie) Why did the LehmanRead MoreEcons1089 Words   |  5 PagesINTRODUCTION TO MANAGERIAL ECONOMICS Dr. Gong Jie National University of Singapore Why Do We Study Economics ï  ¶ People have to â€Å"Choose† â™ ¦ Resources are scarce. â™ ¦ There is No Such Thing as Free Lunch! ï  ¶ Economics: the science of Rational Choice â™ ¦ Rationality: the basic assumption â™ ¦ Rational Choice: Economic agents use all the information available to make decisions that most efficiently satisfy their needs and achieve stated objectives. â™ ¦ How do people make rational choice? This is the subject of