The phrase "a substantial policy" is correct and usable in written English.
It can be used when referring to a policy that is significant or considerable in scope or impact.
Example: "The government has introduced a substantial policy aimed at reducing carbon emissions over the next decade."
Alternatives: "a significant policy" or "a considerable policy".
That amounted to a substantial policy shift.
TiEcon delegates said it could easily be the foundation for a substantial policy on entrepreneurship.
Originally, the deal included a substantial policy reform: a per capita limit, which would have helped to stem the programme's soaring costs.
That led to an angry retort from Treasury Secretary Lawrence H. Summers, who wrote in a memorandum to Mr. Clinton that such a release would amount to a "substantial policy mistake" and would, at best have a "modest effect" on prices.
The product of an aborted previous attempt at moving civil servants out of the south east of England, DfID is the only department to have a substantial "policy" presence in Scotland, and the only department to have a significant number of senior people north of the border.
Allocating inspection resources over a diverse set of imports to prevent entry of plant pests and pathogens presents a substantial policy design challenge.
Congress is needed for any substantial policy switch, he said.
What's more, as Cassidy says, the politics of security and counterterrorism may stand in the way of any substantial policy changes.
Critics of the mayor point less to any substantial policy failures than to what they called Mr. Fenty's unresponsive and at times even arrogant decision-making process.
He has not presented any substantial policy or platforms.
It's not obvious what the Chinese are seeking to achieve yet, but this is a very substantial policy move, that has been rather overlooked.
