Why do some countries ban gambling?

Answer 1

Usually on the grounds that it violates some religious precept. Sometimes on the (debatable) grounds that it encourages crime. But mostly because of the money and political opportunism.

Gambling is often linked to organized crime. Partially because it is a network good; The more players the more value to each individual player. It is more profitable when managed centrally, thus setting it outside the skill set of most stand alone criminals.

Gambling represents a stream of income and governments seek to tax such things, this increases the cost to gamble and so motivation is created go around government influence. Gambling is often absorbed by governments, and to limit competition, they heavily regulate it or make it illegal. A great example is the American lottery.

Any demand for an illicit activity will create an illicit market. Historic and contemporary examples of various forms of prohibition amply demonstrate this. Ironically, the very act of making gambling illegal often leads to a self fulfilling prophecy in terms of increased crime by making gamblers criminals.

This serves the needs of politicians rather well, since being "tough on crime" is easy since criminals have no overt political power. Thus when the question of deregulating gambling is brought up there will never be a shortage of political opposition, regardless of validity of either side of the debate.

Gambling also is opposed on the grounds that it encourages dishonesty. Depending on the game in question this has a measure of truth. Poker players for example can profit heavily if they can deceive (or penetrate the deception of) their opponents.