The issue of Arab demographics before and during the pre- and early Zionist period has long been a sore point.
There is a book called From Time Immemorial: The Origins of the Arab-Jewish Conflict over Palestine by a non-Jew, Joan Peters. She set out to write a book favorable to the Palestinian cause. In fact, the original grant to do the research was paid for by pro-Arab groups in the Middle East and England.
Upon doing the research, however, she came to the conclusion that the entire Arab-Palestinian claim was a lie. Through meticulous documentation, Peters shows that a large fraction of the Arab population starting in the 19th century and continuing through the period of the British Mandate were not descendants of long-term residents of Palestine at the time of the formation of Israel in 1948. In other words, the majority of Arabs in Palestine were every bit as much newcomers as the Jews!
Needless to say, despite extensive documentation her book was criticized by opponents of Israel because, whether true or not, it demolished their political position. Be that as it may, hers is a voice crying in the wilderness.
What Peters and others found out is that the indigenous Arab population had been very small and only began rising with the arrival of the Jews. That was not a coincidence. When the people of the First Aliyah (Eastern European settlers from 1891-1901) arrived they hired Arab laborers for all the agricultural processes that they were embarking upon. For instance, most of those who picked the vineyards were Arabs. They were paid a wage far higher than they could ever earn on their own.
That guaranteed that more Arabs would come to the country. Indeed, with every successive wave of Jewish immigration the Arab immigration doubled and tripled, because there was now opportunity that was not available anywhere else in the Arab world. Why should they stay in the squalor of Egypt, Syria, Jordan or under the absentee Arab landlords of Palestine?
The 15,000 or so Jews who arrived with the First Aliyah brought in with them almost 80,000 Arabs. In effect, the more Jews the more Arabs – except that the Arabs were geometrically increasing while the Jews were only arithmetically increasing. By the time the State of Israel was formed the Arab population was about two million compared to about 600,000 for the Jewish population.
This was Joan Peters’ point. The Arab population of Palestine grew with the Jews. The vast majority had not been there for 1,700 years. And those who came in the modern era came in great part because of the Jews, not just coincidentally with the Jews.