The Effect - - Regression
9 important questions on The Effect - - Regression
13.1.1 Error terms, what is an error term?
13.1.2 Regression Assumptions and Sampling Variation, what are the assumptions?
- Exogeneity Assumption
- Assumption that ε is uncorrelated with any variable we want to know the causal effect of
- There is no perfect multicollinearity
- You can’t make a perfect linear prediction of any of the variables in the model with any of the other variables
13.2 Getting Fancier with Regression, what does this section entail?
- It introduces how we can also work with different variables rather that continuous variables, for example, discrete variables (often binary variables, ie yes/no, or categorial variables)
- It introduces how we can transform variables.
- It introduces how the relationships themselves might be affected by other variables, through interaction.
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
How can we interpret the binary variable's coefficient (the effect of that binary variable on our model)?
for example, if we ran the regression Sales=β0+β1Winter+ε, where Winter is a binary variable that’s 1 whenever it’s winter and 0 when it’s not, then β1 would be how much higher sales are on average in Winter than in Not Winter.
Also, we only include one side of the yes/no equation.
How do you handle categorial variables?
What do you do when you want to interpret the coefficient of one of the categorial variables you made binary?
You do this by dropping one of the categorial variables, this will be the reference variable.
With binary variables, the coefficient gave you the difference between yes and no, now with the categorial variables and reference variable, the difference will be between this category and the reference category.
Ie. The means average income in Gambia is .5 higher than average income in France.
How do you figure out wheter a categorical variable has a significant effect as a whole?
This takes the form of a 'joint F-test'.
What are the two ways to make regression work if there is not linear relation?
- Add Polynomial Terms
- Transform the Data
How can you interpret the regression model when you have polynomial terms?
You do this by using the derivative.
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
