Projects with no cost of capital

It is generally accepted that any project has an appropriate cost of capital reflecting its riskiness and that this cost of capital can be employed to calculate the project's net present value (NPV). Consequently, any future cashflow with a positive expected value has some positive present value. We show that this is not generally true. A risky cashflow with a positive expected value may have a negative present value if the cashflow is correlated with market returns. Thus, there are many realistic projects for which no cost of capital exists. We suggest a simple test to screen out such projects.