In each case below, suppose the government wants to raise domestic produciton to Qs', which occurs at point * on the domestic supply curve. Regrardless of the policy option, to produce Qs', domestic suppliers must receive P' instead of Pf.
 

Small country importer:

Policy option	Pb (buyers)	Qd	Ps (sellers)	Qs
Tariff: shift Pf up by the size of the tariff ($)	P' = Pf+$	Qd', where D crosses P'	P' = Pf+$	Qs', where S crosses P'
Quantitative restriction (QR): shift S right by the amount of the QR (q). The original S shows the domestic supply, and S+QR shows the total supplied, including licensed imports.	P', where S+QR crosses D	Qd', where D crosses P'	P'	Qs', where S crosses P'
Production subsidy (psub): shift S down by the size of the subsidy ($). The original S shows the true MC of each unit, but Spsub shows the lower amount sellers need to charge buyers, since the psub covers the rest.	Pf	Qd, where D crosses Pf	P' = Pf+$	Qs', where Spsub crosses Pf (same Q as where S crosses P')

Small country exporter:

Policy option	Pb (buyers)	Qd	Ps (sellers)	Qs
Export subsidy: shift Pf up by the size of the export subsidy ($)	P' = Pf+$	Qd', where D crosses P'	P' = Pf+$	Qs', where S crosses P'
Production subsidy (psub): shift S down by the size of the subsidy ($). The original S shows the true MC of each unit, but Spsub shows the lower amount sellers need to charge buyers, since the psub covers the rest.	Pf	Qd, where D crosses Pf	P' = Pf+$	Qs', where Spsub crosses Pf (same Q as where S crosses P')