The Household, Income and Labour Dynamics in Australia Survey (HILDA) examines trends in economic well-being among 25,000 people in Australia unfolding over many years. As is true of most longitudinal studies, this need for years of data collection results in high costs. By contrast, a relatively straightforward fitness study, such as one that is merely trying to identify the percentage of regular exercisers in a city who do weight training, may not need a large budget because ______blank