Study after study provides evidence that compensation is the most important motivator up to some individual range/level, at which point its leverage quickly tapers off. Food & shelter would definitely be below the cut-off but a 5% increase could be huge for some and meaningless for others. The challenge is everyone's curve is going to be different.

This list jives with the internal motivators that appear to drive really great work above the survival level: safety, opportunity and recognition.