Overall, venture-backed U.S. real estate-focused companies that went public in the past two years are down an average of 85% from their offering price, according to a Crunchbase analysis. None are above their offering prices.

As foreign investors and home buyers lose confidence in China’s property market, developers are offering cars and pigs to boost sales. WSJ examines ads and policies to see how the country’s real-estate turmoil could ripple out into the global economy. Pho...