I have two data sets. Data set A: data about lifestyles, health conditions and SOCIOECONOMIC and Data set B: data about travel behavior and also SOCIOECONOMIC. We don't know whether they are the same respondents (there is no ID or similar information to match respondents), but we do know these data sets are made from two different surveys. Since both data sets have SOCIOECONOMIC variables, how can I combine these two data sets? Is there any statistical tool to do this? Is there any software that has tools to do this? Please, if applicable, suggest some articles or tutorials. Thanks