Answer:
Free rider problem.
Explanation:
The free rider problem in the economics determines the type of the market failure. The goods are under produced, over degraded or over used. The non excludable goods are included in the free rider problems.
Kevin's team are developing plastic knee replacement. The team continuously producing the goods but the specialist are contributing little in this. The goods cannot be avoided as they are useful for human kind and cannot be avoided.
Thus, the answer is free rider problem.
