No DiagnosticReport written despite repeated system crashes

Question

Hello.
My system crashes about once a day. The mouse pointer is still moveable, everything else is frozen (using the mouse pointer—clicking—does as little as all other keys). Only solution (I know of) is holding down the power button to shut down the computer entirely.
Now, I understand that under mavericks, diagnostic reports are supposed to be found either in
/Library/Logs/DiagnosticReports/ (System Diagnostic Reports),
or in
~/Library/Logs/DiagnosticReports (User Diagnostic Reports),
also they should be accessible through Console.
But they aren't. This seems to lead to the conclusion that there are none written. This is a bit of a problem when trying to determine what causes those crashes.
Any idea why, and what to do about it?

Answer 1

If you have more than one user account, you must be logged in as an administrator to carry out these instructions.
This procedure is a diagnostic test. It makes no changes to your data.
Please triple-click anywhere in the line below on this page to select it:
syslog -k Sender kernel -k Message CSeq 'n Cause: -' | tail | awk '/:/{$4=""; print}' | pbcopy
Copy the selected text to the Clipboard by pressing the key combination command-C.
Launch the built-in Terminal application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.
Paste into the Terminal window by pressing the key combination command-V. I've tested these instructions only with the Safari web browser. If you use another browser, you may have to press the return key after pasting.
Wait for a new line ending in a dollar sign ($) to appear below what you entered.
The output of the command will be automatically copied to the Clipboard. If the command produced no output, the Clipboard will be empty. Paste into a reply to this message.
The Terminal window doesn't show the output. Please don't copy anything from there.