This article develops an integrated theory of budgetary politics using U.S. government expenditure data from 1791 to 2010.

Drawing on three major approaches—decision-making theories (incrementalism and serial processing), policy process models, and path dependency—the authors demonstrate that the incrementalist budget model inherently leads to exponential growth over time unless disrupted by critical junctures.

The research identifies three periods of pure incrementalism across U.S. history, separated by breaks associated with wars or economic collapse. It shows how deviations from this pattern occur during crises but are quickly restored afterward.

Key Takeaways:

• Exponential growth is the default trajectory under normal budgetary conditions
• Policy shifts only happen at critical moments and then return predictably to the exponential path
• Temporary bends reflect localized political dynamics, though spending consistently returns to long-term trends