Probabilistically, a higher level of debt means we are at risk of having our hands tied when we may need to spend badly.

FORBES: How Risky Is The U.S. Level Debt?

Should Europeans permit eurobonds, they would create a large and attractive continental debt market which could profit by lower interest rates ( as the United States does, despite a much higher level of public debt).

FORBES: Eurobonds or Not Eurobonds ?

The level of Japan's debt is higher, relative to its economy, than even some of the crisis-stricken European countries.

NPR: Japan Gyrations Underline Economy's Vulnerability

The first measure comes from the Bank of International Settlements, which found that if private debt as a share of GDP accelerates to a level 6% higher than its trend over the previous decade, the acceleration is an early warning of serious financial distress.

WSJ: Ruchir Sharma: China Has Its Own Debt Bomb

Is there a possibility that at some point, again like in a real estate partnership, the U.S. debt will rise to such a level that you start having to pay a higher rate of interest?

FORBES: S&P U.S. Debt Downgrade: Implications For Commercial Real Estate