Etymology helps.

Eco: house, household, or dwelling place.

The -logy suffix is 'science'. So ecology is: the scientific study of how living organisms interact with one another and with their physical surroundings.

The -nomy suffix is a field or system of something.

Economy is the ecology of finance. Or, Economy is a field of science that predicts financial systems. Any scientific field helps you make predictions, once you know the material. But useful predictions require useful measurement.