arashyazdiha wrote:This sentence was among the Manhattan SC flash cards that I was reviewing: 
If my mother did not attend the London 
School of Economics, she might not meet my 
father, and I might not have been here now. 

The corrected one is :
If my mother had not attended the London School of
Economics, she might not have met my father, and I might not be here
now.

My question is that why the last sentence is not better with present perfect? Isn't it better to be parallel with the former sentence?

Thanks

The presence of 'here' shows the speaker talks about present.

'might not have been' is in past tense (its not present tense). Present tense is shown by 'might not be'.

He could not be a genius or He can not be a genius ==> Present tense
I could not have been a genius ==> Past tense

arashyazdiha wrote:This sentence was among the Manhattan SC flash cards that I was reviewing: 
If my mother did not attend the London 
School of Economics, she might not meet my 
father, and I might not have been here now. 

The corrected one is :
If my mother had not attended the London School of
Economics, she might not have met my father, and I might not be here
now.

My question is that why the last sentence is not better with present perfect? Isn't it better to be parallel with the former sentence?

Thanks

I think present perfect in the last sentence would have been wrong because present perfect has/have symbolizes something which started in the past and continues till present...........if the sentence would have been

If my mother had not attended the London School of Economics, she might not have met my father, and I might not have been here now....

the part in red would mean that u were born earlier than ur mother met ur father,which is wrong...........

hope I make sense

Thanks