Rent-seeking contest with two forms of sabotaging efforts

We study standard rent-seeking contests in which there are two forms of sabotaging. This study is conducted for a symmetric model of two contestants with complete information, when the first form of sabotaging negatively affects the probability of winning the contest while the second form increases the marginal cost of the standard rent-seeking effort. We show that only those forms of sabotage that increase the marginal cost of the rent-seeking effort affect the productive rent-seeking effort. Thus, from a designer's point of view, if monitoring is feasible, the only form of sabotaging effort that should be monitored is the second one.