If we were to think about the tribe of Levi from the perspective of an economist, a serious question would arise.

The Leviim are entitled to 10% of all the agricultural produce, while they do not contribute anything to the economy, as they don't have their own land, and consequently cannot cultivate it. They don't participate in the war effort: "they do not go to war like the rest of Israel." All they have to do is to sing in Beit HaMikdash and to open and lock its gates.

 In fact, they do something in addition. They teach Torah to Am Israel. "They will teach Your statutes to Yaakov and Your Torah to Israel (Devarim 33:10). Additionally, they keep watch in the Temple. "In three places the Cohanim keep watch in Beit HaMikdash, and the Leviim in twenty-one places (Middot 81, 41). In other words, they are responsible for Avodat HaShem of Am Israel. They desist from worldly pursuits and dedicate themselves to holy matters for Klal Israel.

As the Rambam say in his golden language (at the end of Seder Zeraim):

"And why did Levi not receive an inheritance in Eretz Israel and in its spoils with his brothers? Because he was especially chosen to serve HaShem and to minister to Him, and to teach the masses His upright ways and His righteous laws, as it says: "They will teach Your statutes to Yaakov and Your Torah to Israel."

Therefore they were separated from worldly pursuits: "They do not go out to fight in wars like the rest of Israel, they do not inherit (in the Land) and do not receive their station by their own efforts but rather they are the host (legion) of HaShem, as it says: "HaShem will bless his host" and He, the Blessed One, bestowed them, as it says: "I am your portion and your inheritance."

Am Israel needs holy men (not merely men of intellect). This is a communal need, and it is worthwhile to pay for this. Why? Because we are a holy nation and we need holy men who will elevate and sanctify us. Men who will sanctify us in Torah, who will sanctify us in Beit HaMikdash and who will be our lighthouse and our spiritual compass.

If there is anyone who the state is obliged to aid them financially, to provide for them and to exempt them from the yoke of secular affairs, they are not soccer players or movie stars, and not men of "culture" or of the media. They are the scholars who learn Torah lishma (for its own sake), the educators of the generation, "who are differentiated to serve HaShem, and to teach the masses His upright ways."
 

Indeed, not everyone who wishes to attain the name (to be considered worthy) may come and collect a stipend and the portions of the Cohanim, but one who devotes himself to this with all his heart and soul - he is worthy of this, as the Rambam says further:
 

"And not only the tribe of Levi alone, but any and every one in the world whose spirit motivates him and gives him the understanding to separate himself and stand before HaShem to serve Him and minister to Him, to know HaShem and to walk upright as HaShem made him, and to break off from his neck the yoke of the many calculations which men pursue – behold, this one has sanctified himself to be the holiest of the holy, and HaShem will be his portion and inheritance forever and ever, and He will provide him his needs in this world, as He provides the Cohanim and the Leviim."

May our place be among them!