U.S. House Speaker John Boehner (R-OH) speaks during a GOP news conference on the "fiscal cliff", on Capitol Hill in Washington, November 28, 2012. Boehner voiced optimism that Republicans could broker a deal with the White House to avoid year-end austerity measures, saying on Wednesday that Republicans were willing to put revenues on the table if Democrats agreed to spending cuts. REUTERS/Yuri Gripas

The biggest obstacle to a bi-partisan deal for avoiding the fiscal cliff involves an inability to agree on specific, common goals. The underlying aim for Democrats is to close gaps between rich and poor by raising taxes on the wealthy; the deepest goal for Republicans is to slow the growth of government by cutting spending.

Both sides, however, already recognize the urgent need to boost revenues while simultaneously reducing expenditures. This year, government spending reached one-quarter of GDP—close to a seventy-year high—while receipts amounted to only 15.8%, close to a postwar low. Over the next decade, spending must decline to its Bush-era average of  20%, while revenue returns to its Clinton-era average, 19%. If the two parties could agree on these or similar numbers, they could begin to work together to fill in the details.