With the crime of stealing (geneiva), the Torah is very specific about how the theif must pay as a penalty for his crime (e.g. depending on the circumstances, the thief could be liable for double the value of the stolen object, or as much as four or five times its value -- see Ex. 21:33-22:14). Based on the concept expressed in the commandment קדֹשים תהיּּו (Lev. 19:2) -- that we should seek to be holy -- our sages understood the sin of theft to include גניבת דעת -- literally “stealing of the mind,” which includes various forms of misrepresenting oneself and misleading others. Chullin 94a. The concept of גניבת דעת has been applied to such relatively simple concepts as holding a "closing sale" when you have no intent of closing, or cheating on the Regents exam (Igros Moshe (HM 11:30). In theory, it could apply to under-reporting income on your tax returns, or election fraud, however I can't find authorities who speak to either topic specifically. Some authorities consider גניבת דעת a Torah prohibition (see, e.g., the Ritva (Chullin 94a) and the Semag (154)) while others see it as Rabbinic when not involving commerce (e.g. the Shulchan Arukh Ha-Rav). My question is that since what is stolen in this case is a person's trust, is there a way to measure restitution or penalty, and would the measure of restitution/penalty be similar to other types of theft?
The poskim discuss the idea that gezel akum, as opposed to ta'us akum, is prohibited. The two reasons that are given are because it moves into the normal realm of gezel, or because it is geneivas da'as. The Sha'ar Hamishpat (Siman 348 sif katan 2) says that the practical difference between the two is restitution, because geneivas da'as has no restitution. He seems to assume it is obvious that geneivas da'as has no monetary restitution.
Additionally, the Pischei Choshen (Hilchos Geneiva V'Ona'ah Ch. 15 #38) in discussing the prohibitions in C.M. 228 of artificially enhancing the appearance of a product, through fluffing or otherwise, comments that they are all only assur lechatchila, but they are just geneivas da'as and therefore do not have any monetary ramifications.
Rav Moshe Feinstein in his above referenced discussion of cheating on the regents only gets into the monetary aspect when it has left the realm of geneivas da'as and became actual geneiva, since money is being taken unjustly.