A single word to customers when they walk into a shop is a powerful deterrent to crime.
Saying something to a potential customer when they walk through the door reduces incidence of crime significantly.
Welcoming customers with a word when they walk into a shop is a highly effective deterrent to crime.
英訳１：walk into ...で「…に（歩いて）入ってくる」、deterrent は「抑止」の意味です。
英訳２：reduce は「減らす」、incidence は「発生」、significantly は「大いに」の意味です。
英訳３：effective は「効果のある」という意味です。
また、highly はやや堅い言い方なので、 very や really などに言い換えることもできます。
その他の言い方：
- It's possible to significantly reduce the incidence of crime by saying a single word to customers when they walk into a shop.
- The crime rate drops significantly when shop attendants say something to customers when they walk in.
A greeting at entry can dramatically lower the crime rate.
Floor staff can effectively reduce in-store troubles by greeting customers.
A greeting at entry can dramatically lower the crime rate.
いただいた質問をそのまま英訳したものです。
dramaticallyは「劇的に」。
Floor staff can effectively reduce in-store troubles by greeting customers.
こちらは表現のバリエーションとして挙げてみました。
effectivelyは「効果的に」。
in-storeは「店内の」。
アメリカ合衆国 
日本 
