(FORTUNE Magazine) – THE FINANCIAL markets tremble. The dollar glides down, or perhaps begins a dangerous free fall. The world has an urgent question: Is anyone in charge in the White House? Almost as urgent: Who will be assuming charge a year from now? Six Republicans and six Democrats are running to succeed Ronald Reagan. After a year of crises ranging from the stock market crash to the Iran-contra scandal, voters are desperately seeking a strong leader among them. ''People want a hard-nosed, knowledgeable chief executive,'' says Norman Ornstein, a resident scholar at the American Enterprise Institute. ''This is not a time of tremendous concern about issues.'' But while style may overpower substance -- as it does in most campaigns -- issues will still count. Should the U.S. sign an agreement with the Soviets limiting intermediate-range nuclear forces (INF)? Should the country proceed with President Reagan's Strategic Defense Initiative, otherwise known as Star Wars? What about aid to the Nicaraguan contras trying to overthrow the Sandinista government? These are pressing questions. But unless the U.S. goes to war -- in the Persian Gulf or elsewhere -- questions about the economy will be more important than foreign policy issues. How should the U.S. cut the budget, raise revenues, reduce the trade deficit? FORTUNE asked the 12 candidates to respond to these questions, and more. Their answers appear on the following pages. A COUPLE OF generalizations apply to both Democrats and Republicans. First, many candidates have thought a lot about domestic fiscal policy, such as how to cut the budget and how to raise revenues. But by and large they have little to say about international economics. An exception is Congressman Jack Kemp, who believes governments should once again back their currencies with gold. One of the big disadvantages of a gold standard, however, is that economic policies are held hostage to the fluctuating demand for gold. Second, the poorer a candidate's chances of getting elected, the clearer are his ideas. An axiom of American politics in the age of single-issue voting is that a front-runner can only lose support by being specific. If he suggests a modest increase in user fees for national parks, for example, campers might mobilize to bring him down. Only a candidate with little to lose can afford to be tough and specific. Like Pierre (Pete) du Pont, the former governor of Delaware. He has the support of just 2% of Republican voters, according to the polls. But when it comes to cutting the budget, du Pont would spill blood. He proposes phasing out agricultural subsidies, which cost taxpayers $23 billion in the past fiscal year. Bruce Babbitt, the former governor of Arizona, who gets only 1% of the Democratic vote, wants a 5% national sales tax, which he says would raise at least $40 billion a year. Many economists like the idea of taxing consumption and thereby encouraging saving, but no other candidate has had the gumption to suggest it. And Babbitt may drive away elderly voters with his proposal to fully tax Social Security benefits of people with incomes over $25,000; currently those retirees pay taxes on only part of their benefits. At the other extreme sits Senate Minority Leader Bob Dole. By nature he is witty and pointed, but the higher he climbs in the polls the murkier his thoughts become. He has long been committed to balanced budgets, but he also stresses his compassion for the handicapped, the poor, and other outsiders. Fair enough, but how does he reconcile the two principles? What, as reporters ask Dole day in and day out, is his vision? Rather than address the question directly, Dole presents himself as a master politician. That could be a mistake. Republican Kevin Phillips, publisher of a newsletter called American Political Report, maintains that by his vagueness Dole creates the impression that no differences separate him from President Reagan and Vice President George Bush. If Republican voters perceive Dole that way and the economy stays solid, says Phillips, Bush will get the nomination. ''Dole can't sell just the aroma of confidence,'' says Phillips. ''He has to have a cutting edge to distinguish himself from Bush.'' Bush is easy to locate. The loyal Vice President is reluctant to step away from the President's policies. Recently, in fact, he has been out-Reaganing the boss. The President, against his convictions, says he is willing to discuss raising revenues with Congress as part of a budget compromise. Bush will brook no tax increases; he talks only about tax cuts, specifically lowering the tax on capital gains to 15%. That may please some voters, but it won't win much support from poor people. Furthermore, it would negate the tax simplification goals of the 1986 reform act. WHAT IF THE economy falls apart in 1988? Ordinarily the party out of power would benefit. But because none of the Democrats has a persuasive economic agenda, a recession could damage them as badly as any Republican. Simply put, voters might not trust them to manage the economy in hard times. ''The Democrats have been so intimidated by seven years of Reagan's success and popularity that they've become evasive and fumbling about economic issues,'' says Ted Van Dyk, a consultant to many Democratic candidates over the years. The Reverend Jesse Jackson, currently the Democratic front-runner, proposes reducing the deficit by keeping tax rates high for upper-income people. Jackson has also considered a delay in indexing, which keeps inflation from pushing taxpayers into higher brackets. But he is now having second thoughts. Such a policy would hurt the middle class as well as the rich. As a last resort, he would impose a $5-a-barrel fee on imported oil. Jackson is unlikely to win the Democratic nomination. But if he makes a strong showing in the Southern primaries as expected, he will arrive at the convention with a large number of delegates and therefore considerable influence over the party platform. The economic program of the second-in-the-polls Democrat, Governor Michael Dukakis, is provincial, based largely on his success in Massachusetts. Dukakis raised $82 million by declaring a tax amnesty at the end of 1983. Because delinquents paid up readily, Dukakis says the way to raise federal revenues is to collect some of the $110 billion annually that the IRS believes tax evaders do not fork over. He would declare an amnesty, then follow it up with an educational program to help taxpayers fill out their returns. Finally, he would crack down. What made the scheme a success in Massachusetts, and 17 other states, was the warning that state tax collectors, who had been permissive before, would start penalizing crooks. By contrast, the IRS has long sent enough people to prison to be a credible threat. Hiring more IRS agents and educating taxpayers is a good idea that would probably more than pay for itself. But it will not help much in balancing the budget. As the chances of recession increase, Congressman Richard Gephardt's protectionist program sounds more like a quick way to choke off world trade. His amendment to a bill now in Congress would require Japan and some other countries that run trade surpluses with the U.S. to reduce them 10% a year or face mandatory retaliation. Although most politicians believe the amendment is dead (and Reagan has threatened to veto any trade bill with provisions so restrictive), Gephardt continues to back it. He has also sponsored another bill that would let farmers form cartels to limit the production of grains and livestock. Because the cartels would drive up prices, he says, the government would no longer have to subsidize farmers. But unless other countries agreed to raise their prices too, American foodstuffs could not compete in world markets, and the U.S. would have to erect a tariff wall or put quotas on cheaper food imports. The Democrats still have time to broaden and rework their economic ideas. One bystander, who is happy to give advice to any Democrat who will listen, says the candidates should make half a dozen major speeches outlining a comprehensive economic program over the next few months. He says: ''If I were in the race, I'd have a detailed budget proposal out by now.'' The speaker: Gary Hart.

CHART: NOT AVAILABLE CREDIT: NO CREDIT CAPTION: THE REPUBLICANS DESCRIPTION: Candidates' stand on several issues, and FORTUNE's comments.

CHART: NOT AVAILABLE CREDIT: NO CREDIT CAPTION: THE DEMOCRATS DESCRIPTION: Candidates' stand on several issues, and FORTUNE's comments.