HW1: Empirical study: does R&D investment improve corporate
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HW1: Empirical study: does R&D investment improve corporate performance?
Hints: provide your answers to the following questions in a word file, submit your do-file, raw data file (the final merged data file in form of dta) and log-file.
1. Download raw data from CSMAR databank, specifically data on balance sheet, income statement, valuation, innovation and industry information. (Please drop observations of financial companies, ST/SST companies, select sample period from 2010 to 2019);
2. Import data into STATA and generate numeric variables for firm identifier and year for each dataset and save data file in form of dta;
3. Reduce datasets (dta data files) to unique firm*year observations on annual basis and by selecting report type A (A= Consolidated Statement);
4. Merge these three datasets with "Merge" command and make sure the merging process goes flawlessly;
5. Generate following variables, namely R&D intensity (R&D expenditures over sales), log-transformed total asset as firm size, capital structure, asset tangibility, current ratio, growth of operating income and tobin's Q (using tobinq_a); winsorize all continuous variables at 1% and 99% level;
6. Summarize these variables, generate descriptive statistics (including number of observations, mean, standard deviation, min, max) and provide brief description of them;
7. Generate Pearson correlation coefficients matrix (when the pair of variables is significantly correlated at 1% level, put a star behind the correlation coefficients) and analyze two things, i: is the relationship between y and our test variable significant? ii: whether there is serious multicollinearity problem?
8. Plot scatters of tobin's q against R&D intensity, as well as the linear and quadratic fitted lines;
9. Generate year and industry dummy variables;
10. Design your empirical model and run OLS (do not forget to control for year and industry fixed effects);
11. Provide analysis on the main specification and the economic and statistical significance of our variable of interest, R&D intensity, and make your judgment of the contribution of R&D investment;
12. Run post-estimation tests to identify whether full rank condition and homoskedasticity condition hold. If not, provide your recommendations on improving the empirical specification;
13. Design your own moderator and justify the reasoning behind it, run the moderating effects test, report your result and analyze what's the interpretation;
2023-03-25