A political scientist is conducting a study on whether dictatorships or democracies are more effective. She collects data on economic growth in many various countries, some of which are dictatorships and some of which are democracies. She chooses countries for her study by choosing from a list of all 200 countries. She uses a coin toss to determine from which countries she will collect data. At the end of a year, she finds that average economic growth is greater in dictatorships than in democracies. Considering the research design described above, does this study have high or low internal validity? Explain