Economic or economical:
Economic: adjective - of or relating to economics; relating to, or based on consumption, production and distribution of goods and services; of or relating to an economy; possessing practical or industrial significance or uses; affecting material resources; the science of economics.
Economical adjective - marked by careful, efficient, and prudent use of resources; operating with little waste or at a saving; sparing.
So, a person is not generally economic, but it may be that the same person uses economic theory and practice to determine the most economical use of resources. Anything that is economical is generally characterised by saving money or resources.
‘The economic indicators all showed that the country’s finances were in serious debt following the disastrous collapse of the banking system at the hands of greedy and imprudent bankers.’
‘Caroline was so economical with the truth that it was difficult to give credence to anything she said.’
Picture: a farm nestling in the ripening wheat fields a short walk from my home.