In this chapter, we have formalized a theory of ethics, treated as endogenous values in socioeconomic development. The nature of such ethical endogeneity entails organic learning between entities, variables, institutions, and policies. A new theory is thus introduced as being different from the way economic theory treats ethics as external to the economic system for estimating value impacts in terms of purely economic variables. We have also shown that such ethical values and their impact in the socioeconomic development process are quantifiable. In this regard, estimation is done to explain the ethical process in socioeconomic development. At the end, we note that participation in socioeconomic development being premised on the epistemic roots of laws and guidance of unity of knowledge is truly a bold example of ethical endogeneity in participatory socioeconomic development.