Dockworkers are back to the negotiation table with employers, and automation is a big sticking point. Mechanizing port operations can make them more efficient, but the Longshoremen’s union is concerned that efficiency comes at the price of jobs. The deadline to avoid a possible strike is next week. Also in this episode: probing the mysteries of Spotify’s powerful algorithm, snowplowers take a hit from climate change, and the trade deficit isn’t as bad as it looks.