China is Starbucks' 2nd biggest market, but sales are slumping. Here's why.

• Starbucks' comparable sales in China are slumping, with a 14% drop in the most recent quarter.
• Its then-CEO put it down to weak consumer spending and a coffee store "price war" in a July investor call.
• China is Starbucks' second-biggest market but analysts question how well its format works in China.

Starbucks has been struggling in China.

Comparable store sales, a key measure for the restaurant industry, were down 14% in its most recent quarter.