…debt can be used to finance four different financial transactions:
1. productive investment
2. innovation
3. consumption
4. speculation

The first two add to the productive capacity of an economy. When the government builds roads, dams that produce hydro-electric power, or other infrastructure projects, debt is being used productively. Similarly, when debt is used by companies for research and development or new ventures, it may lead to the production of new goods or services, which then can lead to an expansion of GDP.

Debt that is used for consumption, however, is considered a dissipation of capital. Nothing is produced; rather, something is consumed. After something is consumed—such as a basic necessity like food—the debt remains even though the item consumed no longer exists. When debt is added for consumption purposes it enables the debtor to pull tomorrow’s demand forward into the present. As debt is used to expand consumption in the present period, it is in essence borrowing from the future therefore reducing future demand.

Debt taken on for speculative purposes is also unproductive as it can lead to asset bubbles or overinflated prices for assets. Eventually all asset bubbles go bust. The overinflated asset values decline but the debt still remains. Think of the recent housing bust and the technology bubble as an example of speculative bubbles financed by debt for unproductive purposes.

from this article.

So, “Is debt good or bad?”

My response, “Debt for what?”