Even as leading cabinet ministers openly advocate a division of Jerusalem, a new report on the problems inherent in such a move has garnered little attention. This disregard is remarkable for two reasons. The first is the report's provenance: the Jerusalem Institute for Israel Studies, a respected left-wing research institute that has hitherto been a leading proponent of dividing the capital, and whose proposals have served as the basis for successive Israeli offers to do so from 2000 onward. The second is the report's chief revelation: that the dramatic erosion in what was once a wall-to-wall consensus against dividing Jerusalem has been based almost entirely on faulty premises. There is little doubt about the reason for this erosion; it is cited by virtually every leading advocate of division, from Vice Premier Haim Ramon on the government's left flank to Yisrael Beiteinu Chairman Avigdor Lieberman on its right. That reason is demography: Israel's 1.3 million Arabs already constitute almost 20 percent of the country's population, and since their birthrate is higher than the Jewish one, they could well become an even larger percentage of the population down the line. Getting rid of some 200,000 east Jerusalem residents would ease this danger, proponents of division argue. And unlike other Israeli Arabs, east Jerusalem residents are not Israeli citizens; hence the problems inherent in depriving someone of citizenship would seemingly not exist. But what the new JIIS report, compiled by former Foreign Ministry legal adviser Robbie Sabel and doctoral student Gilad Noam, reveals is that in fact, these problems do exist - because east Jerusalem Arabs are permanent residents, and under Israeli law, permanent residents have almost all the same rights as citizens. Thus while Israel can cede east Jerusalem neighborhoods, it cannot cede east Jerusalem residents, the report says: They would have to be offered the option of moving elsewhere in Israel. And it requires no great intelligence to realize that most of them would exercise that option - not because they love Israel, but because Israel has jobs, and the Palestinian Authority does not. The power of this motive can be seen in Palestinian migration patterns since 2000. Because Israel virtually ceased granting work permits to Palestinians after the intifada began, those who work here now are generally doing so illegally. As illegals, they live in constant fear of arrest, and they are frequently brutally exploited, since they cannot complain to the authorities for fear of deportation. Moreover, they literally risk their lives to get here: Every year, some Palestinian job-seekers are shot while crossing the border because the security forces mistook them for terrorists. Clearly, nobody who was not desperate would come here under such circumstances. Yet in fact, some 100,000 Palestinians are thought to be working illegally in Israel, and the security services say that dozens, and sometimes even hundreds, of Palestinians attempt the border crossing every day. GIVEN THIS reality, it is inconceivable that 200,000 east Jerusalem Arabs would give up the right to do legally what tens of thousands of their brethren risk their lives to do illegally - namely, work in Israel. Almost certainly, most would opt to remain. But not only would dividing the city do nothing to improve Israel's demographic balance, it would significantly worsen Israel's financial balance: Since permanent residents and citizens have almost identical rights, the report said, residents of any neighborhoods Israel cedes would be entitled to compensation, whether they choose to go or stay. Those who choose to remain Israeli residents will, like the Gaza settlers, have been forced to leave their homes by a government decision to withdraw from the areas in question. They could thus presumably demand the same compensation: for their homes, for moving expenses and, in the case of those who would be giving up local jobs or businesses, for loss of income as well. Those who opt to remain in their homes and give up their Israeli residency, in contrast, will lose valuable benefits such as Israeli health insurance and social security. And since that loss, again, will have resulted from Israel's decision to abandon these areas, they, too, would be entitled to compensation, JIIS argues. In short, dividing Jerusalem would more than triple the amount of compensation Israel would have to pay its own residents under any agreement. Hitherto, most Israelis have assumed that at most some 80,000 settlers (those outside the settlement blocs) would have to be evacuated and compensated. But if JIIS is correct, dividing Jerusalem would raise the number of Israeli residents entitled to compensation to some 280,000. DIVIDING THE capital would also have serious security implications. These are not addressed in the JIIS report, which focuses on legal issues, but they should be obvious to anyone who remembers the daily gunfire on Jerusalem's Gilo neighborhood during the early months of the intifada. Gilo was the only Jewish neighborhood of Jerusalem to suffer in this fashion because it was the only one within rifle range of Palestinian-controlled territory - namely, the village of Beit Jalla. And once the Israel Defense Forces reasserted control over Beit Jalla, the shooting stopped. Were parts of east Jerusalem handed over to the Palestinians, however, numerous other Jewish neighborhoods would become as vulnerable to Palestinian gunfire as Gilo. That would obviously be true of those east Jerusalem neighborhoods built after 1967, such as Pisgat Ze'ev, Neveh Ya'akov and French Hill, but it would also be true of many west Jerusalem neighborhoods, such as Malha and Talpiot - former border neighborhoods that have grown beyond recognition since 1967 (think, for instance, of Malha's mall, Biblical Zoo and Teddy Stadium). The bottom line is that dividing Jerusalem would have ruinous economic and security consequences without improving Israel's demographic situation a whit. And the JIIS report has done a valuable service by bringing these facts to the public's attention. But that service will be wasted unless the public, the media and, above all, opposition MKs begin demanding that the government either find solutions to these problems or drop the whole idea of division.