In 1967, after the Six Day War, Israel introduced modern health care to the territories, as well as an electrical grid and sources for safe drinking water. As a result, the Palestinian Arab mortality rate plummeted and their life expectancy soared.
I am no demographer, but I thought it would be interesting to see roughly how many fewer Palestinian Arabs would be alive today if they had remained under Egyptian/Jordanian rule after 1967.
I based my numbers on the West Bank and Gaza populations as of 1970 (Palestine Remembered) and 2004 (CIA Factbook) to calculate growth rates, and the natural growth rates of Jordan and Egypt today (2.5% and 1.75%, respectively.) The CIA Factbook growth rates for Palestinian Arabs today (3.06% in West Bank, 3.71% in Gaza) are much smaller than what the real population growth during these dates were, so I used the Factbook current population numbers, ignoring the problems that some Israeli demographers have found with these numbers.
I did not account for emigration or immigration into the territories, making the oversimplistic assumption that the population growth is mostly the same as the natural growth. I also did not have accurate historical growth rate data for Egypt and Jordan so I assumed today's rates as being constant over the decades, another gross oversimplification.
Given this back-of-the-envelope calculation, and based again on current population numbers that Palestinian Arabs accept as accurate, I estimate that 1.6 million Palestinian Arabs exist today in Gaza and the West Bank that would not be alive had Israel not occupied the territories after 1967.
In other words, "occupation" was the best thing to ever happen to Palestinian Arabs in their short history.
(If you accept the criticisms about PalArab demographics, these numbers go down to only about 200,000 PalArabs alive because of Israel.)
For what it's worth....