Not enough shekels

 Money is not everything, but it buys most of the things that are.

Values are also important in politics, but the important ones have something to do with money.
For that reason, whoever controls the purse is somewhere near the top of the heap.
In the United States system of presidential government, budget proposals and spending control come out of the Executive Office of the President, overseen by a person appointed and removable by the President. Congress has an important role in the middle (between the budget proposal and its approval), as befitting a system of separately elected office holders.
In a parliamentary system, the Prime Minister is most prominent and usually most powerful, but more as primary among near equals than as the big boss in the presidential model. Where the government is a coalition between parties, the Minister of Finance, especially if it is the head of a party the Prime Minister needs in order to keep the coalition together--may have enough independence to be not all that far below the Prime Minister in terms of power.
Israel is heading for a situation where the Prime Minister is being forced by the numbers to create a government not of his desire. While he leads a party with 31 votes in the Knesset, smaller parties with a total of 33 among them have been demonstrating considerable unity in negotiations toward a coalition. If that unity survives into the government, the Prime Minister may not be the prime mover that he would like.
Indications are that the Finance Ministry will go to the head of one of those "minor" parties. However, the economic situation facing whoever becomes the Finance Minister is reducing the appeal of the position. At least some of the time, minor party heads have been maneuvering to accept anything but the Finance Ministry.
Whoever wins (or loses) the competition will preside over the cutting of expenditures and maybe tax increases. Neither is a way to win votes at the next election, and the combination of both is especially unpleasant. The minister will be able to direct the biggest cuts away from favored programs, but that is less pleasant than directing increases toward the same programs.
Moreover, professionals in the Finance Ministry of Israel, like its parallels elsewhere, comprise the most powerful unit in the government bureaucracy. The Ministry attracts the best graduates of Economics Faculties along with some bright young people who manage to get through the screening despite having majored in something else. New professionals, backed up by department heads who have stayed on despite competing offers from elsewhere, learn how to say no to counterparts in other ministries and even to the heads of other ministries or local authorities. The bureaucrats of the Finance Ministry not only have personal intelligence, experience, and the ministry''s economic data at their disposal, but various laws grant them authority to withhold allocations of money below what the budget has promised.
Those familiar with the British TV comedy, "Yes Minister" (used as a teaching tool in university courses dealing with public administration) saw how the professionals made the minister think he was running the show. However, through a combination of greater knowledge of law, precedent  and implications, the professionals could really be saying "No" when they seemed to be saying "Yes."
All the returns are not yet in. Negotiations continue. The time for Bibi to finalize his government will not be up until later this week. Current betting is that Yair Lapid will take Finance, after being rebuffed in his desire for Foreign Affairs.
Lapid does not have a degree in Economics or anything else. He did not complete the national matriculation exam used for admitting young people to university. He comes from a career in television, knows how to express himself in Hebrew, and wrote an excellent biography of his father, the late media master, political party head, and government minister Tomy Lapid.
Bar Ilan University made a special decision in Yair Lapid''s case, and admitted him to a doctoral program despite his lack of formal qualifications. However, the Council of Higher Education forced the university retract its decision.
Even without a full high school education, Lapid will have his hands in our pockets and upon every public service coming from the national government or local authorities (heavily under the control of national ministries). However, there will be other hands in those matters belonging to the Finance Ministry''s permanent cadre of personnel, each of them with more education and much more experience than the Minister in the complex realm of public finance, with its large numbers and arcane arguments about what influences what. 
Lapid''s qualifications to manage the economy are only one of the problems in the road of what may become Israel''s government. The limited leverage of the Prime Minister is the most prominent, but also to be watched is the learning of Lapid and his 18 party colleagues, plus Naftali Benet and his 11 party colleagues. Almost no one in those two party clusters has much more than the most recent election campaign as serious experience in national government or politics.
Then there is the Palestinians, major chaos just over the border with Syria, lesser chaos  in Egypt, and whatever we can expect from Washington.
Some may say that all this is what Israel needs in order to make a fresh start. Others will view it as an opportunity to test the importance of political experience.