Will NPC villagers contribute to public works projects?

Other flesh and blood players can donate to public works projects, even people just visiting your town, not just other residents! Hope for rich friends!

Villagers do contribute towards public works projects, but the amount tends to be so negligible that you'll still end up paying for the majority of the project yourself. They do this automatically, and there's no dialogue option to engage or encourage them to do so.

In my town, the NPCs donate somewhere between 100 to 550 bells a day, but only after I've paid around 6000 bells to the project. Whether it works off a percentage of what you've paid, I'm not sure, but I think that's how it works.