In the Netherlands, access to disability insurance has become gradually more limited and demanding. The same holds for sheltered work. This puts disabled workers, and especially those with no working history, in disadvantaged competition with the non-disabled segment of the working population. In this study, we employ a Lotka-Volterra competition model based on differential equations to investigate how government expenditures for disability and other social benefits interacted in the period between 2010 and 2018. We contribute to the literature by showing that public expenditure for disability is not autonomous and that its competitive power in the social protection ecosystem changes both in type and over time. Our findings suggest that government expenditure for disability benefits in the Netherlands behaved both as prey in favour and predator at the cost of social exclusion and unemployment benefits. Reforms that took place in the ecosystem of interest are used to interpret such behaviour.