A longstanding issue in economics is how income taxes affect government revenue. Proponents of increasing income taxes say that taxing citizens at a higher rate will increase government tax revenue since you are collecting more from each person. Doubters of this policy say that increasing income taxes causes people to find ways to avoid tax or causes citizens to work less, ultimately reducing the tax rate. Given this economic issue, suggest primary and secondary data sources that one could use to test this hypothesis. Explain why the selected data sources are appropriate for the topic.