Two of these studies provide the basis to form ratios of the WTP of different age cohorts to a base age cohort of 40 years.
Ratios of the WTP are based on two of these studies.
mnli hypothesis: Ratios of the WTP are based on two of these studies. premise: Two of these studies provide the basis to form ratios of the WTP of different age cohorts to a base age cohort of 40 years.