STATA Commands for Panel Data

Command 1:

  For Descriptive Statistics, just put the following command and then press enter. 

       summarize

       Or

       summarize y x1 x2 x3…xn

For detail statistics

      summarize, detail

       or

      summarize y x1 x2 x3…xn, detail

Command 2:

   For Correlation Matrix, just put the following command and then press enter.

      corr

      Or

      corr  y x1 x2 x3 …. xn

Command 3:

For Pooled OLS, just put the following command and then press enter.

reg         

Or   

reg y x1 x2 x3…. xn

regress

Or  

regress y x1 x2 x3 …. xn

Command 4:

For Robust Regression, just put the following command and then press enter.

reg y x1 x2 x3…. xn, robust 

Or  

regress y x1 x2 x3 …. xn, robust

Command 5:

   For Durbin Watson test and variance inflation factor (VIF) and Ramsey Reset test for omitted variables, just set the time and run OLS regression and then put the following commands, respectively.

   gen =_n

   tsset time                         (Time Series data)

  reg y x1 x2 x3…. xn

  dwstat

  vif

  ovtest  

Command 6:

   For Hausman test, just set the ID and time for panel data and run GLS regression by the following commands, respectively.

   xtset id time, yearly

   xtreg y x1 x2 x3….xn, re

   estimate store re

   xtreg y x1 x2 x3….xn, fe

   estimate store fe

   hausman fe re

Command 7:

   For Chow test (F-Limer Test or Redundant Fixed Effect), just set the ID and time for panel data and run GLS regression by the following commands, respectively.

    xtreg y x1 x2 x3….xn, re

    test x1 x2 x3 

Command 8:

   For Breusch and Pagan Lagrangian multiplier test for random effects, just set the ID and time for panel data and run GLS regression with random effects and then press the command of LM test, respectively.

xtreg y x1 x2 x3….xn, re

xttest0

Command 9:

   For Wooldridge Test of Autocorrelation in Panel data, run OLS regression and then press the following commands of Wooldridge Test, , respectively.

        reg y x1 x2 x3….xn

        ssc install xtserial

        ssc findit xtserial

        net sj 3-2 st0039

        net install st0039 

        xtserial y1 x1 x2 x3….xn           

Command 10:

   For Cross-sectional time-series FGLS regression, press the following commands, respectively.     

        xtgls y x1 x2 x3….xn

Note:

Coefficients:  generalized least squares

Panels:      Homoskedastic

Correlation:   No autocorrelation

Command 11:

   For Mixed-effects ML regression

 xtmixed y x1 x2 x3 ….xn

Command 12:

   For Jerque Berra test of normality, press the following commands, respectively.

       ssc install jb

    jb y

       jb x1

       jb x2

       jb x3

       jb resid 

How to Email a Professor for PhD and MS Scholarships?

Email plays an essential role when it comes to approaching a professor for scholarships, funding and research supervision.  Content of your email is the first impression which you will give to the professor that will describe you are a serious and well qualified applicant.  So, what is the best way to write an email that can increase your chances of selection for the specific position in the professor lab or research group? Here are the guidelines about the structure and content of the email.

Your email should illustrate that you are a qualified and suitable person for the open position in professor lab. It should be short, clear and concise without repeating the whole details of your CV. Always make the first impression good by reading about the professor’s research projects and mentioning them in your email. Throughout your email keep in mind about grammar and punctuation.  You can find a sample email template for contacting the professor at the end of this article.

1. Subject Line

Normally, professors are busy with their research work and supervision of their students. They can ignore your email. To avoid this problem, always include a strong, attractive and information based subject line for your email.  The subject line will help the professor to guess about the contents of your email even before opening it. We recommend you to always use a clear and catchy subject line. For example, “Request for research supervision Fall 2019”, “Request for PhD supervision”, “Request for MS supervision” or “Prospective PhD Student”.

2. Greetings

Your email should be formal and start with Dear Dr._____, Dear Prof._____ or Respected Prof._____. Always use professional greetings and avoid use of titles like Mr.______, Mrs._____or Ms._______.  After that, you can write a good morning or good afternoon depending on the time when you are sending email to a professor. Moreover, you can include email opening sentences such as “I hope this email finds you well.”, “I hope you’re doing well.”, or “I hope you’re having a great week.”.

3. First paragraph

The first paragraph should be about your short introduction stating about your name and where are you from. It should also address briefly about your qualifications and experience the professor is looking for the open position.  You can include that I would appreciate the chance to discuss with you about your lab projects and research in the area of (write professor’s area of research into which you are interested) and about possible MS/PhD opportunities in your lab or research group. Avoid all kinds of abbreviations and slang terms.

4. Second paragraph

In the second paragraph, you can write about your previous research, work experience or other skills which are relevant to the professor’s research area.  You can get information about current and previous research projects of professor after visiting the official website of the lab. Avoid any kind of complexity, while writing about your previous work experiences and research projects.  You have to list your expertise and achievements in an easy to understand the way that will help you standout from the competition.

5. Third paragraph

The third and last section is the concluding paragraph. Here you need to state your motivation and interests in professor’s lab or research group.  You can mention the specific research areas of professors which fascinated your interests to apply in this lab. Then, you can particularly show your interest in a specific domain.  End this paragraph with polite request to consider you for the open option. For instance, “If possible, I would love to start working on (project name) in your lab beginning this summer.”

6. End email with a formal acknowledgment
At the end of your email, you can mention that CV is attached with the email.  If there is additional information that I have not included that you would like, I would be happy to provide it to you.
I look forward to hearing from you!
Regards,
Your name

Sample email to contact a professor

Subject: Request for Research and MS supervision
Dear Prof.________,
I hope you are doing well and are in good health.
My name is (write your name) and I have completed (your degree title) from (your university name, don’t only use abbreviation)with (your CGPA/total CGPA, don’t mention CGPA if it’s low).  As an option you can write about your big achievements such as Gold Medal and Dean certificates, if you have any.
During my undergraduate/Master, I have worked on some projects to actualize and implement the theoretical knowledge of (write your expertise, e.g. signal processing, automation and smart systems) into practical work. In this paragraph, you can also relate your previous and current work experience, internships, online courses and projects with the professor’s area of interest. If you have any research publication then you can mention in this paragraph
I visited (write professor Lab or Research Group name e.g. Networking lab) website and found that you have research interests in (write research area of professor e.g. 5G, Internet of Things and automation). I am very enthusiastic to conduct research and pursue MS under your supervision.
I have attached my CV with this email and looking forward to hearing from you soon.
I shall be thankful for your response.
Sincerely,
Your Name

Conclusion of this article

The above email is just a sample, we recommend you to write your own email based on the highlighted guidelines. Always send emails to professors during week days using the official email address of your university or company. Don’t use any kind of abbreviations and slang languages.  Don’t attach anything other than CV because adding too many files can end up your email into the spam folder. After 2 weeks, you can send a reminder email to the professor if you don’t get any reply get any reply (Also read these 10 points and how to make academic CV).  We hope you like reading this article and wish you the best of luck for getting your dream scholarship. Please feel free to drop a comment below, and let us know about your views for this article. Like our page Facebook. 

 to never miss any guideline and expert advice.  
Thanks

Thesis Writing-Tips and Tricks

Writing a thesis may be one of the difficult tasks you have to face in your academic life. By selecting a suitable subject and ideas, all the way through to form a convincing and thought-provoking conclusion. This short guide will cover a few tips and tricks about the process that may assist you.

1. Write the Conclusion First

The introduction of a thesis comes first, obviously, but it is actually more common to write that last. Start writing your conclusion first instead – you can always go back and revise it later. The conclusion is what leaves a lasting impression on the reader, and it is your final chance to show how important your ideas are and why they matter.

The conclusion is not simply a summary of everything that came before it, although that is part of it. Instead of a simple summary, you should aim to tie up all loose ends and bring together your ideas and references to solidify the original point. It is also a chance for you to elaborate on the ideas presented earlier in the thesis, and a chance for you to prove that people should care.

Consider reading the conclusion to a friend, perhaps someone not as familiar with the subject matter as yourself, and get them to ask questions. You can even prompt them to be extra critical so that they don’t just go along with whatever you’re saying because they’re a friend. If you don’t wish to invite anyone else in to assist. Just ask yourself, after every point made in the conclusion, why should people care about this? What difference could this possibly make in the life of someone reading it?

2. It’s Not a Mystery Novel

The reader should be aware of what your point is, and how you intend to prove it, before they get too far into reading your thesis. It should not be a mystery, in which the murderer and victim only become known toward the end of the piece, for example.

This type of dramatic third act revelation generally does not go over well when it is employed in a thesis. Your readers are expecting an analytical discussion of your chosen subject, in a style that fits in with academic writing.

3. Don’t Rely on Emotion

It is all too common now to see students become overly emotional in their work, and it shows in their writing. Emotional and heartfelt conclusions do little to further the discourse on a subject, as opposed to being more sophisticated in your analytical paper.

Relying on emotions instead of facts throughout your thesis is a bad habit to get in to, and using this style in your conclusion may undermine all of the good work and research that came before it.

4. Hiring Professional Help

Sometimes we all just need a little help. Whether you are overloaded with work and other duties and need a kick start in the form of a thesis proposal, or the entire paper, there are professional teams of writers available 24/7. So, if you are concerned about privacy then consider ordering from the custom thesis helper on Facebook to take this burden off your shoulders, so that you can focus your time on energy on other aspects of your education or personal responsibilities.

Research Topic Selection and Its Steps

It is the ability to develop a good research topic is an important skill. A tutor may assign you a specific topic, but most often instructors require you to select your own topic of interest. When deciding on a topic, there are a few things that you will do it because it is necessary in topic selection for research.

v  Brainstorm for Ideas.

v  Select a topic that will enable you to read and understand the literature.

v  Ensure that the topic is manageable and that metrical is available i.e. data and literature.

v  Make a list of keywords.

v  Be flexible.

v  Define your topic as a focused research question.

v  Research and read more about your topic.

v  Formulate a thesis statement / Problem Statement

     

Be aware that selecting a good topic may not be easy. It must be narrow and focused enough to be interesting, yet broad enough to find adequate information. Before selecting your topic, make sure you know what your final project should look like. Each class or instructor will likely require a different format or style of the research project. Use the steps below to guide you through the process of selecting a research topic. 

Step-1: Brainstorm for Ideas

Choose a topic that interests you. Use the following questions to help generate topic ideas.

v  Do you have a strong opinion on a current social or political controversy?

v  Did you read or see a news story recently that has piqued your interest or made you angry or anxious?

v  Do you have a personal issue, problem or interest that you would like to know more about?

v  Do you have a research paper due for a class this semester?

v  Is there an aspect of a class that you are interested in learning more about?

Look at some of the following topically oriented Web sites and research sites for ideas.

Are you interested in current events, government, politics or the social sciences?

v  Try Washington file

Are you interested in health or medicine?

Look in Healthfinder.gov, Health & Wellness Resource Center or the National Library of Medicine.

Are you interested in health or medicine?

v  Look in Healthfinder.gov, Health & Wellness Resource Center or the National Library of medicine?

Are you interested in the Humanities; art, literature…etc.?

v  Browse links from the National Endowment for the Humanities.

For other subject areas try:

v  the Scout Report or the New York Times/ College Weblink

Write down any key words or concepts that may be of interest to you. Could these terms help be used to form a more focused research topic? Be aware of overused ideas when deciding a topic. You may wish to avoid topics such as, abortion, gun control, teen pregnancy, or suicide unless you feel you have a unique approach to the topic. Ask the instructor for ideas if you feel you are stuck or need additional guidance.

Step-2: Read General Background Information

Read a general encyclopedia article on the top two or three topics you are considering. Reading a broad summary enables you to get an overview of the topic and see how your idea relates to broader, narrower, and related issues. It also provides a great source for finding words commonly used to describe the topic. These keywords may be very useful to your later research. If you can’t find an article on your topic, try using broader terms and ask for help from a librarian.

For example, the Encyclopedia Britannica Online /the printed version of this encyclopedia, in Thompson Library's Reference Collection on Reference Table 1) may not have an article on Social and Political Implications of Jackie Robinsons Breaking of the Color Barrier in Major League Baseball but there will be articles on baseball history and on Jackie Robinson.

Browse the Encyclopedia Americana for information on your topic ideas. Notice that both online encyclopedias provide links to magazine articles and Web sites. These are listed in the left or the right margins.

v  Use periodical indexes to scan current magazine, journal or newspaper articles on your topic. Ask a librarian if they can help you to browse articles on your topics of interest.

v  Use Web search engines. Google and Bing are currently considered to be two of the best search engines to find web sites on the topic

Step-3: Focus on Your Topic 

Keep it manageable

A topic will be very difficult to research if it is too broad or narrow. One way to narrow a broad topic such as "the environment" is to limit your topic. Some common ways to limit a topic are:

v  by geographical area

Example: What environmental issues are most important in the Southwestern US

v  by culture

Example: How does the environment fit into the Navajo world view

v  by time frame:

Example: What are the most prominent environmental issues of the last 10 years

v  by discipline

Example: How does environmental awareness effect business practices today?

v  by population group

     

Example: What are the effects of air pollution on senior citizens?

Remember that a topic may be too difficult to research if it is too:

Locally confined - Topics this specific may only be covered in these (local) newspapers, if at all.

      Example: What sources of pollution affect the Genesee County water supply?

v  recent - If a topic is quite recent, books or journal articles may not be available, but newspaper or magazine articles may. Also, Web sites related to the topic may or may not be available.

v  broadly interdisciplinary - You could be overwhelmed with superficial information.

Example: How can the environment contribute to the culture, politics and society of the Western states.

v  popular - You will only find very popular articles about some topics such as sports figures and high-profile celebrities and performers.

If you have any difficulties or questions with focusing your topic, discuss the topic with your tutor/librarian.

Step-4: Make a List of Useful Keywords

Keep track of the words that are used to describe your topic.

v    Look for words that best describe your topic.

v    Look for them in when reading encyclopedia articles and background and general information.

v    Find broader and narrower terms, synonyms, key concepts for key words to widen your search capabilities.

v    Make note of these words and use them later when searching databases and catalogs.

Step-5: Be Flexible

It is common to modify your topic during the research process. You can never be sure of what you may find. You may find too much and need to narrow your focus, or too little and need to broaden your focus. This is a normal part of the research process. When researching, you may not wish to change your topic, but you may decide that some other aspect of the topic is more interesting or manageable.

Keep in mind the assigned length of the research paper, project, bibliography or another research assignment. Be aware of the depth of coverage needed and the due date. These important factors may help you decide how much and when you will modify your topic. Your tutor will probably provide specific requirements, if not then the following table can provide a rough guide.

Assigned Length of Research Paper or Project	Suggested guidelines for approximate number and types of sources needed
1-2 page paper	2-3 magazine articles or Web sites
3-5 page paper	4-8 items, including book, articles (scholarly and/or popular) and Web sites
Annotated Bibliography	6-15 items including books, scholarly articles, Web sites and other items
10-15 page research paper	12-20 items, including books, scholarly articles, web sites and other items

Step 6: Define Your Topic as a Focused Research Question

You will often begin with a word, develop a more focused interest in an aspect of something relating to that word, then begin to have questions about the topic.

For example

§    Ideas = Frank Lloyd Wright or modern architecture

§   Research Question = How has Frank Lloyd Wright influenced modern architecture?

§   Focused Research Question = What design principles used by Frank Lloyd  

          Wright are common in contemporary homes

Step 7: Research and Read More About Your Topic

Use the key words you have gathered to research in the catalog, article databases, and Internet search engines. Find more information to help you answer your research question.

You will need to do some research and reading before you select your final topic. Can you find enough information to answer your research question? Remember, selecting a topic is an important and complex part of the research process.

Step 8: Formulate a Thesis Statement

Write your topic as a thesis statement. This may be the answer to your research question and/or a way to clearly state the purpose of your research. Your thesis statement will usually be one or two sentences that states precisely what is to be answered, proven, or what you will inform your audience about your topic.
The development of a thesis assumes there is sufficient evidence to support the thesis statement.

For example, a thesis statement could be: Frank Lloyd Wright's design principles, 

including his use of ornamental detail and his sense of space and texture, opened a new era of American architecture. His work has influenced contemporary residential design.

The title of your paper may not be exactly the same as your research question or your thesis statement, but the title should clearly convey the focus, purpose, and meaning of your research.

For example, a title could be: Frank Lloyd Wright: Key Principles of Design for the Modern Home.

Remember to follow any specific instructions from your tutor.

Practical Exercises to Extend Your Learning

Identify three narrower aspects of the following broad topics. In other words, what are three areas you could investigate that fit into these very broad topics?

v    Pollution

v    Sports

v    Politics

Identify a broader topic that would cover the following narrow topics. In other words, how could you expand these topics to find more information?  

Menus in Michigan prisons
Urban planning in Flint

Imagine that you have been assigned the following topics. Think of 5 keywords you might use to look for information on each.

How does air quality affect our health?
What are the barriers to peace in the Middle East?
Should snowmobiling be allowed in wilderness areas?
How can welfare reform help poor children