When the ``For Sale'' sign went up on the 110-story Sears Tower recently, the word on the street was that the Japanese might buy. In that old aerie of Chicago clout on the fifth floor of City Hall, Mayor Eugene Sawyer raised an eyebrow. He had just heard a forecast that half the downtown of this once-isolationist town would be owned by Japanese-backed interests in 2000.
Then there was a prediction that Japanese futures markets - already expanding their presence here - would surpass Chicago's by the same year.
``Has anyone found the number of properties that they really own?'' the mayor sighed, sounding like the president of some banana republic as he spoke of ``50-cent dollars'' from overseas driving up tax assessments.
In Congress, the flash point in debate over the US role in the global economy has moved from trade to investment, including ``information sovereignty'' or the monitoring of foreign stakes.
That's because in a world economy whose currency is information, data may be the ultimate trade restricter and stimulant in one. But those data can be as elusive as a free-floating exchange rate.
For example, statistics place Japanese real estate holdings in the US at $4.4 billion - and at $18 billion, too.
The General Accounting Office estimates foreign automakers in the US could cost this country 45,000 jobs by 1990 - or add 112,000 new jobs.
When presidential candidate Michael Dukakis blasted foreign ownership of US companies last month, he did so at what he thought was an American automotive plant; its real owner was Italian.
Designed to remedy this, a proposed amendment to this year's US trade bill, known as the Bryant amendment after its author, US Rep. John Bryant (D) of Texas, would have established an expanded system for monitoring foreign investment in the US.
The amendment failed, but the plan was passed in modified form by the House last month.
Reaction was swift and controversial. Among high-level officials and businessmen in Japan last week, author Clyde Prestowitz says the unpassed law was still being discussed as if it were a wartime catastrophe.
Mr. Prestowitz, a former US Commerce Department Japanese specialist, says, ``The Japanese long have had a very sophisticated system for encouraging investment which they thought would encourage a flow of technology into their economy, and screening out investment they thought would do nothing but raise domestic real-estate prices. I think we should have a similar system.''
The objection to the Bryant proposal from the Reagan administration, from foreign lobbyists, and from many American multinational corporations, is that it will hurt the competitiveness of foreign investors at a time when the US is touting free trade abroad.
For investments above a certain size, it would require even privately held companies to disclose information such as the market value of assets. This information supposedly would be available only to members of Congress, certain state and federal officials, and approved researchers. But some fear it would fall into the hands of competitors.
But John Howard of the US Chamber of Commerce, which opposes the proposal, says the primary objection is political.
``It creates new risks for foreign investors, such as hate or anti-foreign campaigns,'' he says. Others express concerns that greater monitoring will spark protectionism and scare off foreign investors whose money is needed to fund the federal government's budget deficit.
Concerns about overseas response to US legislation form the second major issue in the debate: foreign influence.
This year, two national US associations representing foreign investors were formed with prestigious domestic backing. The chairman of the Association for Foreign Investment in America, for example, is former Cabinet official Elliot Richardson.
Sen. Lloyd Bentsen (D) of Texas has proposed banning growing foreign-backed political-action committees; recent ``revolving door'' legislation added restrictions on US officials who retire into jobs with foreign government lobbies.
The third major focus of concern about foreign investment in the US is defense related: Will foreign investment weaken America's military supply and - in time of war - ``surge'' capacity?
Congress this year passed a measure known as the Exon-Florio amendment to the trade bill, giving the President the power to block a foreign acquisition if it could endanger national security.
Defense officials have taken more of a ``free trade'' stance of late, saying they are mainly concerned with keeping the manufacturing of military supplies in the US, regardless of the owner. Classified production lines can be spun off into ``blind'' subsidiaries of foreign owners.
But others have concerns about how long foreign owners may support American defense-related operations, and how an overall technology drain from the US may weaken our defenses.
New Defense Department data bases are seen as ways of tracking US economic weaknesses in critical technology, such as ball bearings, resulting from dependency on foreign sources.
A recent Defense Department report called for creation of an Industrial Policy Committee to be chaired by the national security adviser.
Pentagon consultant Stephen Bryen, who formerly was deputy undersecretary of defense for trade security policy, says the Exon-Florio measure was not focused enough.
``We need to have a law that gives us the possibility of dealing directly with efforts to buy factories and commercial units in this country by hostile countries, and we don't have anything like that right now. It's all ad hoc,'' he says, although Defense Department officials claim current screening systems are adequate.
That relates to the final issue in this debate: Is growing foreign investment in the US bad and, if so, is our current screening of investments adequate?
Many economists and US officials say it's a good contribution to the economy, and directly represents only a small percentage of total US assets - about 5 or 6 percent, up about two points from 1980.
The vast majority of foreign investment is in ``portfolio'' assets here, such as government debt notes or small minority shares of companies.
While this area of foreign investment has received less attention than visible ``direct'' investment - an ownership or controlling interest - some analysts consider it more troubling, because of the potential for foreign economies to influence the US government and US markets.
Some economists and officials say proposals such as the Bryant bill are simply unnecessary, that the statistics collected by the US government on foreign investment here are unparalleled in the world. Available in aggregate form, much of the individual company data are kept confidential, which Bureau of Economic Analysis statisticians view as necessary to maintain accuracy.
But there are also those who say that Congress needs to commit more resources to expanding, coordinating, and speeding up data collection and interpretation, to keep up with the global economy.
Many say such statistics would probably allay American fears more than result in anti-investment measures.
Under a plan advanced by economists Douglas Woodward and Norman Glickman in their forthcoming book, the Commerce Department's Current Interagency Committee on Foreign Investment in the United States (CIFIUS) would be replaced by MIRADOR - the Multi-National Investment Review Agency and Department of Research. The new agency would coordinate both data collection and screening, examining both inward and outward flows of US investment.
One good outcome of what may sometimes may be irrational concerns over foreign investment could be better information on the global economy and on domestic mergers and acquisitions, Mr. Woodward says.
He thinks the Bryant bill has flaws, but adds, ``The only reason we know anything about foreign investment right now is because of the paranoia about the Arab investment in the 1970s,'' which resulted in setting up much of America's current data-collection system.
``That's what's so odd about it,'' he says. ``If it wasn't for those fears we would know very little about what the Japanese were doing in the 1980s. I think we can turn this debate around and make this a positive thing.''