This has always been something that's bothered me, even when I was just a little kid. Were kamikaze attacks used by Japanese pilots effective in the sense that it was a sustainable approach to warfare? I have no doubt that it was effective the first time around, when American sailors would just be shocked at such a suicidal tactic, but even with that in mind (and the attacks sinking 34 ships, and damaing 368 others) I thought it was monumentally wasteful.
First, it takes time and money to build the plane. I have no clue how much it would have taken to build a typical Japanese warplane, but I'm betting it wasn't cheap or easy. By the time Japan was using kamikaze attacks as a standard tactic, they were already being pressed for resources and time, so I don't think crashing a perfectly good plane as its sole method of attack is particularly helping the country's war effort.
Consider using the same plane for dropping bombs and torpedoes. Even if you've got a 10% chance of scoring a hit on a moving ship with a bomb, and a 10% survival rate on sorties, you'd still at least get 1 pilot out of every 100 surviving, living to fight another day. Whereas, with kamikaze attacks, survival and a successful "hit" are mutually exclusive event, so you don't get that 1 pilot coming home to go off and kill more ships.
Granted, I may be vastly oversimplifying the mechanics of killing. Hitting a ship with a bomb doesn't guarentee a kill, whereas I'm led to believe that kamikaze attacks, when they did succeed, were more likely to guarentee a kill. Still, if the USAF is to be believed, then roughly only 8.5% of ships that were the targets of successful kamikaze attacks were actually sunk. That's not a very impressive number, though I have no comparison for the number of ships sunk with conventional air power. Wikipedia implies that 8.5% of the attacks sinking ships is a phenomenal thing. The 8.5% also does not include the ships that were simply damaged beyond repair. While not as glorious as sinking a ship, I suppose that counts as a kill.
The opportunity cost of the crashed plane is also a bit worrying, in my opinion. That plane could have been shooting at a bomber dropping bombs on Japanese factories, or strafing enemy infantry on a beach, or just dogfighting with enemy planes. If my sole objective was to be as big of a pain in the ass as possible to my enemy, I should think that protecting infrastructure, so that you could be a pain in the ass for a longer time, would be more important that possibly taking out an enemy ship, unless it was an aircraft carrier. I also think that keeping the plane and the pilot intact so that he could continue to kill people would be more beneficial than sending that pilot off to die.
Now, we get to the pilots themselves. Training them takes time and money as well, though probably less time and money than regular pilots. I would assume he would need to learn only the basics of flying, and landing the plane would not exactly be a priority, though it would be a waste if the pilot crashed his training plane or whatever. I would assume these suicide pilots wouldn't necessarily need air combat training, but then again, I'm not too sure. My gut tells me that, rather than giving these pilots the basics then sending them off, you may as well invest the extra time and money to make him a real combat pilot, so he can go off and kill the enemy. That being said, if anyone knows how much more time and money needs to be invested to make a pilot combat worthy (after he's learned to fly and do basic maneuvers and whatever), it'd be nice if they could tell me. If the amount of time and money required to complete the training is significant, then perhaps I could concede that kamikaze may be a better way to use the pilot than in a regular role.
I guess my biggest logical disconnect is that, if you were a nation losing a war, running lower and lower on resources and manpower, yet you refused to give in and were determined to give your enemy one hell of a fight to the bitter end, wouldn't it make more sense to prolong that fight than rather than using tactics that, in my opinion, are just inherently wasteful? It could be because I was brought up in a culture that valued each individual life, so perhap's that's colouring my judgement about how to use the pilot's life, but I'm not too anxious to toss the plane away on a suicide attack either.
I realize that the kamikaze attacks are also from a cultural disconnect. Even in North America, I can understand dying in the service of your country, provided your country is doing the right thing in the first place, is a noble cause, but that's because we're going in with the assumption that everyone should try and stay alive, and that trying to stay alive is the natural thing to do. I can understand, academically, that for the Japanese soldiers of WWII, dying for their country was a great honour, but does that honour "outweigh", so to speak, the honour of having a massive kill tally and being alive? I know that sounds a bit childish - like screaming "HAHA! NUB! I GOTZ MOAR KILLZ DEN JOO!" or " I HAVE A HIGHER KILL/DEATH RATIO THAN YOU!!!!" into the mic when playing Counterstrike, but it goes back to my assumption that you'd want to be the biggest pain in the ass for as long as possible to your enemy if you're fighting a losing war.
I also realise that this is a somewhat simple or bleak view of war. You win a war by taking away the enemy's capacity to wage war - whether through blowing his roads and fuel lines and stuff up, or killing every soldier he sends to fight, the goal is still to take away his ability to wage war. So, I suppose kamikaze attacks could have been effective as a strategic method of waging war, but my gut still tells me "no", but in a conventional war and in a bloody last stand scenario.