Why is there a 14-year difference between the submission date of this arXiv paper and the date in the paper text? I am so confused. This paper is listed as having been submitted in 1999, but the date below the author's names inside the PDF is 2013. 

What is the meaning of each date?
The LaTex source code contains the \date{\today} command, which inserts the current date at the time of compilation. That is, the PDF is probably last regenerated in 2013. The arXiv submission history gives a more reliable date.