Monthly Archives: July 2018

Stata command to convert string GVKEY to numerical GVKEY or vice versa

The default type of GVEKY in Compustat is string. Sometimes, we need it to be a numerical type in Stata (e.g., when we want to use the super handy command tsset). The command to convert string GVKEY to numerical GVEKY … Continue reading

Posted in Stata | 1 Comment

Stata command to calculate the area under ROC curve

If we want to evaluate the predictive ability of a logit or probit model, Kim and Skinner (2012, JAE, Measuring securities litigation risk) suggest that A better way of comparing the predictive ability of different models is to use the Receiver … Continue reading

Posted in Stata | 1 Comment

Stata commands to calculate skewness

Suppose we are going to calculate the skewness of 12 monthly returns. The 12 returns may be stored in a row (Figure 1) or in a column (Figure 2). This post discusses how to calculate the skewness in these two … Continue reading

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Use Python to download lawsuit data from Stanford Law School’s Securities Class Action Clearinghouse

[Update on 2022-01-08] I am grateful to my research assistant, Shiyu Chen, for her excellent work in this update. This website requires login now. A function was added for login and access to the protected content. The code may terminate … Continue reading

Posted in Python | 14 Comments