Existing research has focused on budget officers' intertemporal decision-making but has not addressed the problem that budget officers tend to underestimate future outcomes in the budget process. This study experimentally investigates how messages containing behavioral economics “nudges,” addressing the underestimation, influence budget officers' assessments. We conducted a survey experiment with responses from 484 budget officers in local governments throughout Japan. Respondents assessed a hypothetical environmental policy program budget, after having been randomly assigned to one of four groups, each given a different set of information and messaging: (A) baseline information (including future outcome information), (B) additional information with a loss-framing nudge, (C) additional information with a social comparison nudge, and (D) no baseline information. The results show that budget officers in the two randomly assigned nudge-based intervention groups gave higher evaluations of future outcomes than those in the baseline group with no nudges, whereas the assessment of the baseline group is statistically not significantly different from the group without any information.