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In policy debate, impact calculus is a type of argumentation which seeks to compare the impacts presented by both teams.
Basic impact calculus
There are three basic types of impact calculus that compare the impacts of the plan to the impacts of a disadvantage:
- Probability (one impact is more likely)
- e.g. Economic collapse is more probable than an outbreak of grey goo, therefore the risk of economic collapse outweighs the risk of a grey goo disaster.
- Timeframe (one impact will happen faster)
- e.g. An asteroid impact will cause extinction before Global warming will, therefore an asteroid impact outweighs Global Warming.
- Magnitude (one impact is bigger)
- e.g. Nuclear war kills more people than car accidents.
Other types of impact calculus
Some other more sophisticated arguments are also considered impact calculus:
- Impact inclusivity (one impact is inclusive of the other)
- e.g. Global war is inclusive of a Taiwan war, therefore global war outweighs Taiwan war.
- X creates Y (one impact causes the other impact to happen)
- e.g. War causes genocide, therefore war outweighs genocide
- Internal link shortcircuiting (one impact prevents a (positive) impact from happening)
- e.g. Nuclear war halts space colonization, therefore nuclear war outweighs space colonization
- e.g. Civil liberties lost in the name of security during a time of crisis can be restored later, but deaths caused by a lack of security are irreversible.
Framework arguments can also be considered impact calculus. Arguments as to why the judge should adopt a utilitarian or consequentialist perspective or conversely a deontological perspective may change the way they compare impacts.
Impact calculus and "new" arguments
Basic impact calculus arguments may be made at any time and are generally not considered "new" arguments, even if brought up for the first time in the 2NR or 2AR. More sophisticated forms of impact calculus should generally be brought up earlier in the debate and evidenced if possible.