This is actually one of the best authors people can read from. Regarding your second link, Krugman has already admitted his prediction did not come to pass.
On a number of issues Krugman has proven a good deal more accurate than other economists, such as:
-Whether or not Federal Reserve would cause inflation
-Whether the stimulus in 2008 would help the economy
-Whether or not Obamacare would work
and more on his near daily blogging/tweeting.
Sure he's definitely made mistakes, but who hasn't, and at least he has owned up to them.
