
Campaign promises can change who votes for whom. This analysis uses a sharp eligibility rule tied to children’s dates of birth to estimate the causal impact of a German conservative party’s pledge to expand social benefits on party alignment.
📌 How eligibility was identified
- A regression-discontinuity design exploits the cutoff in children’s date of birth that determined eligibility for the promised benefit.
- The pledge under study was a clear, targetable expansion of social benefits announced by a German conservative party.
📊 What the data show
- The pledge increased alignment with the pledge-making party by 12.7% among eligible beneficiaries.
- Effects were larger for individuals who traditionally supported left-wing platforms and for those with lower economic security.
- There was no evidence that the promise mobilized previously inactive voters.
📈 How the effect behaved over time
- The alignment boost proved transitory: re-alignment among recipients disappears shortly after the pledge is fulfilled.
💡 Why this matters
- The design provides strong causal evidence that targeted campaign promises about social benefits can temporarily attract voters from competitor parties.
- The findings highlight limits to promise-driven realignment: gains accrue mainly among eligible, often economically vulnerable voters and do not persist once benefits are delivered.