Studies have failed to show that an increase in helmet use has led to a decrease in serious head injuries. This is unsurprising given the likely confounding variables, such as the number of participants, the type of skiing, the average speed etc... Experts agree that there has been an increase in risk taking behavior. In recent years, many resorts have built terrain parks, and advances in equipment have made it easier to ski faster and perform tricks. Ordinary ski helmets are not designed to protect you from landing on your head from a 5 metre high jump, or from hitting a rock at anything over 25 mph. If you want protection in these circumstances, you’ll need to wear a full-face motorcycle-style helmet, just like the ski racers do.
The important point is that studies have shown that helmet use DOES decrease the number of less serious head injuries, which is by far and away the most common scenario.
One argument against helmet use is that the weight of them can cause the head to be thrown around in a fall, increasing the chance of neck injury. But studies have shown this is not a significant risk. It may be true that wearing a helmet reduces your hearing or peripheral vision, impeding your awareness of other slope users, and increasing your chances of a collision. To some extent this effect has been mitigated with modern helmet design, but this is no substitute for keeping your wits about you on our ever more crowded slopes.
My advice is use your head, and wear a helmet!
For options on buying a helmet... visit Ellis Brigham