Possible counterexamples (there are probably better ones):
“It’s the economy, stupid”
http://sub.garrytan.com/its-not-the-morphine-its-the-size-of-the-cage-rat-park-experiment-upturns-conventional-wisdom-about-addiction (http://lesswrong.com/r/discussion/lw/ing/open_thread_september_1622_2013/9rdu)
http://parenting.blogs.nytimes.com/2013/08/25/its-not-a-problem-its-called-being-a-child/
For each of those, the meaning of “it” is clear from context. If it weren’t, then it would be uncommunicative writing.
All of these are dummy subjects. English does not allow a null anaphor in subject position; there are other languages that do. (“There”, in that last clause, was also a dummy pronoun.)
Possible counterexamples (there are probably better ones):
“It’s the economy, stupid”
http://sub.garrytan.com/its-not-the-morphine-its-the-size-of-the-cage-rat-park-experiment-upturns-conventional-wisdom-about-addiction (http://lesswrong.com/r/discussion/lw/ing/open_thread_september_1622_2013/9rdu)
http://parenting.blogs.nytimes.com/2013/08/25/its-not-a-problem-its-called-being-a-child/
For each of those, the meaning of “it” is clear from context. If it weren’t, then it would be uncommunicative writing.
All of these are dummy subjects. English does not allow a null anaphor in subject position; there are other languages that do. (“There”, in that last clause, was also a dummy pronoun.)