'increase uncertainty' is correct and usable in written English.
You can use it to indicate a situation in which something is more uncertain than it was before. For example, "The recent trade tariff disagreements between the US and China have increased uncertainty in the global economy."
volatility increase uncertainty in their revenues.
"It is not the moment to fuel or increase uncertainty".
"It is a disgraceful attempt to undermine the scheme and increase uncertainty over its future," she said.
An extensive wrangle about its share of the debt would increase uncertainty and hence its funding costs.
The ECB would cede much of its monetary powers to a fledgling capital market, which might increase uncertainty.
Moreover, the new regulations being discussed in Congress are tending to increase uncertainty in financial markets, another drag on recovery.
The letter also fails to explain why the ozone rule would increase uncertainty, as compared with the uncertainty created by litigation over the Bush Administration rule.
But other parts could restrict trade in a way that would ultimately hurt American consumers and increase uncertainty for American companies.
The Census Bureau cuts would increase uncertainty about the state of the economy, the drivers and drags on growth and the effectiveness of business and government policy.
Moreover, points out Nick Bloom, a British economist at Stanford University, events that increase uncertainty, measured by the volatility of American share prices, are fairly frequent.
William Charnley, a partner at the law firm King & Spalding, said: "In the short term, Brexit would increase uncertainty and would continue to limit investor demand for risk assets and therefore continue to inhibit capital raising".
