can the marginal product of capital be negative
Marginal product In the "law" of diminishing marginal returns, the marginal product initially increases when more of an input (say labor) is employed, keeping the other input (say capital) constant. Here, labor is the variable input and capital is the fixed input (in a hypothetical two-inputs model). As more and more of variable input (labor) is employed, marginal product starts to fall. Finally, after a certain point, the marginal product becomes negative, implying that the additional unit of labor has decreased the output, rather than increasing it. The reason behind this is the diminishing marginal productivity of labor.
Negative and positive rights Under the theory of positive and negative rights, a negative right is a right not to be subjected to an action of another person or group—a government, for example—usually in the form of abuse or coercion. As such, negative rights exist unless someone acts to negate them. A positive right is a right to be subjected to an action of another person or group. In other words, for a positive right to be exercised, someone else's actions must be added to the equation. In theory, a negative right forbids others from acting against the right holder, while a positive right obligates others to act with respect to the right holder. In the framework of the Kantian categorical imperative, negative rights can be associated with perfect duties while positive rights can be connected to imperfect duties.[citation needed]