Over the years our society has indexed a number of things--Social Security is indexed to the consumer prices, ETF's are indexed to various indices, income tax rates are indexed to consumer prices, etc. Some social programs are means-tested and indexed to income.
An index has two advantages IMO: it allows for gradual changes and it establishes a linkage between social factors. The gradual change is important: big changes get more recognition than gradual ones. And psychology tells us that people get upset by the perception of loss, an upset which isn't balanced by their appreciation of gains. "Graduating" has similar effects.
I think we, especially liberals, should take more advantage of indexing. For example, in 1993 the Clinton administration backed off its energy tax because of opposition from rural Democrats, particularly senators, and saw an increase in the gas tax as a fallback. But what we should have done is index the gas tax to inflation. The effect would have been roughly to double the value of the tax.
Another example: Obamacare was passed with a mandate, a financial penalty for not enrolling. What would have happened if we had graduated the penalty, Lessening the initial pain might have enabled the mandate to be preserved, instead of repealed by a Republican Congress.
“Major policy decisions”? Do we know what that means? There’s a standard of economic impact of $100 million for regulations–but that’s been unchanged since it was first adopted in the 1970s in relation to inflation concerns, not policy.
Arguable the USDA/Trump decision to spend billions from the Commodity Credit Corporation was a major policy decision. But it wasn’t particularly controversial, because it was too esoteric and there were no significant opposing voices to make a fuss. https://www.forbes.com/sites/stuartanderson/2020/01/21/trump-tariff-aid-to-farmers-cost-more-than-us-nuclear-forces/?sh=4fe7a4966c50
I suspect the operational definition is an issue about which there’s a big fight between the parties and/or interest groups. I think the reality is such issues don’t get resolved in legislation, just kicked down the road to the faceless bureaucrats who can be blamed if they screw up and/or offend people.