Loess spans and data stories

How do local regression curves affect polling interpretations?

Anthony B. Masters
Jun 17 · 3 min read

Vote intention polls help inform the public about the state of political parties. Are the parties are gaining or losing vote share? Even when headline estimates appear stable, there can be an evolving churn underneath.

Local regression

The good people of Wikipedia update a list of opinion polls, and produce a simple smooth curve: