Following a shopping centre brawl in Melbourne at the weekend, Victorian Premier Jacinta Allan announced the state will ban the sale of all machetes from Wednesday.

In March this year, the Victorian government had already announced that from September 1 machetes would become a "prohibited weapon".

Prohibited weapons are items considered inappropriate for general possession and use without a police commissioner's approval or a Governor in Council Exemption Order.

This means machetes will be added to the list of things - such as swords, crossbows, slingshots, pepper spray and about 40 other items - that are essentially banned.

Possession of a prohibited item can result in penalties of two years imprisonment or a fine of more than $47,000.

Victoria is the first state in Australia to outright ban machetes. In other jurisdictions, machetes (like knives) may be used for lawful purposes, and are "controlled" or "restricted" - meaning you need a reasonable excuse or valid reason for possessing one.

Most jurisdictions (except Tasmania and the Northern Territory) prohibit sales to minors.

Allan said the sales ban will have no exceptions, meaning nobody will be able to purchase a machete.

However, machetes are a useful tool, particularly for agricultural purposes, and outdoor uses such as camping.

When the new laws come into effect in September, people will be able to apply for a special "commissioner's approval" to possess a machete. The exact details of who may be granted an exemption, and under what circumstances, are not yet clear.

Nor is it clear whether people will have to, for example, pay for a permit to own a machete, or what measures people may have to take to prevent unauthorised access or theft.

Despite alarming headlines and political rhetoric about a knife crime epidemic, it is hard to say exactly how much of a problem knife crime is.

Statistics about weapon use and unlawful possession are not always disaggregated by type of weapon.

Crime statistics are notoriously slippery, and what looks like a "crisis" can often be the result of changes in policing practices. For instance, when police run an intensive operation searching for knives in public places, they are more likely to find knives in public places. This does not necessarily mean there are more people out there carrying knives.

The one crime where statistics are fairly clear is homicide: knives or other sharp instruments have long been the most common weapon used in Australia.

The actual number of homicides involving knives or sharp instruments has stayed relatively stable over time. When you take into account the increase in how many people live in Australia, the rate per head of population has fallen.

It is tempting to think a machete ban would reduce these figures even more. Unfortunately, violence prevention is not that simple.

Homicides that involve people using their hands and feet have declined markedly over time. Why has this "method", which is available to anybody, fallen so much? The answer is: nobody really knows.

This tells us we need to look beyond types of weapons.

Violence is complex and simple "solutions" may make people feel safe (at least temporarily) but seldom deliver real results over the longer term.

It's easy for governments to ban things, which is why they do it so often. But we should pay close attention to what Victorian Police Minister Anthony Carbine said in March:

This is Australia's first machete ban, and we agree with police that it must be done once and done right. It took the UK (United Kingdom) 18 months - we can do it in six.

Lawmaking should never be a race. Nor should politicians be mere mouthpieces doing what police tell them.

Police are the ones we turn to for protection when violence breaks out, but this does not mean they are the only ones we should go to when we are looking for the most effective ways to deal with problems.

Tackling violence takes serious commitment to complex and intensive programs that focus on the root causes, particularly among at-risk families and disadvantaged, marginalised youth.

This is hard work that takes a long time, includes many different stakeholders, and seldom sways votes. Focusing on the choice of weapon is simply a distraction.

There is no question the sight of machete-wielding youths storming through a busy shopping centre is terrifying. People should be able to go about their business without fearing they will be attacked.

But reducing violence takes a lot more than banning one particular weapon, as Victoria will likely find out.