For communities that do have a different proportion of jobs in each sector, what could explain this difference?"

Communities that have a different proportion of jobs in each sector of the economy are those communities that have a specific industry or production that is especially relevant to the regional or national economy. Thus, for example, rural towns in Wisconsin depend almost exclusively on the production of milk and other dairy products, while large cities such as New York or Los Angeles depend on the service sector and other cities located in the Rust Belt depend on the industrial sector.

ń, wǒ shuō yīngyǔ, dàn wǒ huì shuō qítā yǔyán, rú xībānyá yǔ fǎyǔ yìdàlì yǔ hé pǔtōnghuà, suǒyǐ bùyào pànduàn, dànshì