自動販売機の経済学
●Tyler Cowen, “The economics of vending machines”（Marginal Revolution, May 20, 2008）
Japan has so many, but why?
・・・(略)・・・
First we must look to the shortage of storage space in homes. I suspect few Japanese want to buy big piles of stuff at Costco. So buy smaller "portions" and in the meantime the inventories are stored in the vending machines, where they are more or less at your disposal.
Cars of course are another means of storage and also a way to transport goods in bulk (NB: you carless people have a hard time pigging out at the public library, you poor souls). But most Tokyo residents don't use cars so again they buy goods in smaller numbers which again points us to the vending machine. Buy one disgusting sweet fizzy juice, drink it on the spot, and walk to your nearest vending machine when you need another one.
●Linda Choi Hasunuma, “The Ubiquitous Vending Machine:Jido-hanbaiki”（Two Minute Japan, UCLA Asia Institute, 2001）
So, why are they ubiquitous? Well, think of Japan's very high population density, and the severe lack of space (not to mention it's commercialism!) Without the room to store groceries, more frequent shopping trips become necessary. The Japanese tend to do more daily shopping for their groceries by foot, or by bicycle. Cars are expensive to own, register and park, so you see more two wheelers on the streets with baskets for carrying groceries. Compare this to the US where we usually go once a week or so to a supermarket or price club and store our week's supply of groceries in our larger refrigerators and cupboards. Space is also an issue for the proprietors. Local merchants can make money outside of their small shop by having vending machines outside on the street. Plus, with virtually no problems with vandalism, this further contributes to the low risk and profitability of these machines. These unmanned machines eliminate the need for a human clerk to warm up the food or ring the register, so may also be more economically efficient.
●Tracey Jones, “Jidoohanbaiki - japanese vending machines”（Essortment.com, 2002）
●Michael I. Colwill, “Vending Machines Craze in Japan”（Dark Roasted Blend, September 20, 2007）
なぜ日本には自動販売機がこんなにたくさんあるんだろうか？（Hasunuma氏の記事によると、23人ごとに1台ずつの自動販売機、とのこと）
日本人はシャイ（対面で買い物するのが恥ずかしい）だから？
治安がいい（路上にお金が落ちているにもかかわらず、それが拾われる*1おそれがあまりない）から？
上で引用したようにCowenとHasunuma氏は日本に自動販売機がこんなにも溢れている理由を日本の住宅事情に求めている。
居住スペースが狭いために一度にたくさんの商品を買い溜めしておくことができない→頻繁に買い物に出掛けなければならない（車ではなく徒歩あるいは自転車で出掛けるとなると一回の買い物で購入できる量も限られる）→自動販売機の活躍する余地の出現。
つまりは頻繁に買い物に出掛けることは厄介であり、その厄介さのコストが自動販売機の必要性を生むということである。
居住スペースの狭さを補うもの＝自動販売機であり、自動販売機＝家の外にある冷蔵庫ということになるであろう。
