This question should be asked with a big ‘IF’. If these two countries were together what would be the demographics of the subcontinent at this time. Even the world would have been a different place had these two countries been together. The economic, financial and political equations of the sub continent would be different too.
The two states were born in the august of 1947 on the basis of religion. But along with it started the unending woes of the people on both sides especially at the border regions. But if the partition hadn’t taken place India would have been a very different country. To start with India would have been ahead of China in terms of population which is not a very good statistic to go with. There would have been a better stability in the subcontinent due to the non existance of the so called “Kashmir issue”. Infact it is this Kashmir that is the reason for the instability between the two countries right from the time of partition. Even wars are being fought on this very reason with no solution in sight. Whenever a communal discord happens anywhere Hindus advocate the fact that Pakistan was created for Muslims and so they should go there. The same rhetoric is heard in Pakistan too. But if we were combined the ratio of Hindus and Muslims would be at an equal level which would have helped decrease the hatred between the two religions.
With a peaceful Kashmir all the money that is being used for improving our defense forces for protecting the valley could have used for better means. The economical and financial growth would have been better than the current one. The Pakistani region would have been a better developed one than the current war zone like region. More importantly with no groups fighting the war of terrorism against India the whole of subcontinent would have had less terrorists. Even the foreign affairs with other countries would be different too with India being a trustful ally of US and getting all the funding for helping out in the Afghan war.
Other than these political and economic issues there are other things to look for. Of course we would be a better cricket team than the present one and we could have excelled in other sports. Even in science and technology we could have used the brains of eminent Pakistani scientists. Our Bollywood would have had a better reach in Pakistani region too which can be used to increase their revenue.
Its more than 60 years now since these two countries have parted ways. What about joining the two now? Well, at least in the present circumstances it is not boud to happen. Whether this region would have been better or worse without partition the debate can continue. But at the end we have to live in two separate countries. Lets hope that the friendship between the two countries grows in future and not hatred.