An American economic slowdown, he said, "won't have a visible impact on high oil demand and it won't have a visible impact on high oil prices".
Government cuts have had a visible impact on this dire situation.
Towner said there was no visible impact on the ground where it was found.
No Hollywood studio chief, no captain of industry, and probably no recent American politician, had a more visible impact on people's lives.
So far, these Title IX compliance reviews haven't had much visible impact on campuses beyond inspiring a few complaints from faculty members.
The six-week conference, intended to settle longstanding disputes among clans, produced upbeat resolutions but had no visible impact on a raging insurgency in Mogadishu.
The Supreme Court ruling on Tuesday is not likely to have an immediate visible impact on Jemaah Islamiyah, said Sidney Jones, a leading expert on the organization.
"It won't have a material visible impact on the market but it is still the appropriate thing to do at this time".
Nowhere is this clearer than in Washington, where dozens of federal programs dispense billions of dollars with no visible impact on the performance of students or schools.
In the past two years, two new drugs have reached the market that are having a highly visible impact on certain forms of breast cancer and leukaemia.
But over the last year, low-fare airlines, including Southwest, JetBlue, America West and Frontier, have invaded the transcontinental market, with a visible impact on their operations.
