1. It’s not really a proposal — it’s just a set of headline numbers without specific policies. The letter says Republicans want to cut $900 billion from mandatory spending and $300 billion from discretionary spending, but they don’t say what or how they want to cut. The letter nods toward a proposal sketched out by Erskine Bowles, the cornerstone of which is a gradual increase in the Medicare age, but it lacks specifics. …

2. The description of tax reform makes little sense. It’s feasible to raise $800 billion from base broadening over ten years, but not to raise $800 billion and finance a significant cut in tax rates. Even if you capped all itemized deductions (including for charity) at $25,000, that would only generate about $1.3 trillion in new revenue, leaving $500 billion available to finance rate cuts. …

3. The proposal does not fully avert the fiscal cliff. Republicans describe their proposals as a way to “avert the fiscal cliff.” But this proposal would only partly delay the implementation of austerity measures (tax increases and spending cuts) into future years when the economy is stronger.