London — Almost 12 million people are out of work in North America. The figure is 161/ 2 million in Western Europe. Unemployment is a growing threat to personal lives and to the entire Western, noncommunist economic system.
Now one of the countries hardest-hit, Britain, has come up with three new ideas to reduce its own jobless rate of almost 13 percent, or 3.2 million people - an all-time record.
The ideas, which have had reactions ranging from lukewarm to hostile so far, are as yet largely untried. They include:
* Doubling the number of ''enterprise zones'' in which new businesses are exempt from local taxes for 10 years. They can also write off 100 percent of new commercial and industrial buildings, and are freed from some irksome regulations and paper work.
* Putting a hoped-for 130,000 people who have been out of work for at least six months on community and voluntary jobs such as building church walls, digging gardens for the elderly, and repairing village halls.
* Trying to spur industries to split one job between two people, either between two unemployed individuals who would work half-time each, or between one full-time worker and one unemployed one (again, both working half time), or between two full-time workers if one of them is about to be fired and his job eliminated.
The plan (full details have not yet been released) is to offer companies an incentive payment per job - somewhere in the region of (STR)500 ($890). Ministers are pleased because they say the savings in unemployment benefits would more than offset the cost of the payments.
One snag: Half-time workers will want to make sure their pension rights are maintained.
The three plans are being watched with intense interest across Western Europe , especially in France, where unemployment is around 8.25 percent, and in Italy, where it is nearing 10 percent.
Already the ''enterprise zone'' idea has been tried out in the United States on a small scale.
The three-idea package is a measure of the political and economic gravity of unemployment in Britain today. The government of Prime Minister Margaret Thatcher is doing well in the opinion polls. It has a comfortable majority of between 30 and 40 votes on most issues in the House of Commons. But 3.2 million unemployed are a continuing tragedy.
Mrs. Thatcher says that inflation may well be down to 71/2 percent by the end of this year. She is holding public spending firmly in check and refuses to pump in more public funds as the Socialist government has done in France.
But pressure to do more for the jobless has proved politically as well as economically imperative.
The question is whether the new measures will, or can, do much good.
Evidence on the enterprise zones is inconclusive so far, although the government sees some hopeful signs.
A report by consultants to the government published earlier this year found that although many companies have applied to go into the zones, they tend to be ones squeezed for land rather than those looking to meet more demand.
A new report later this year may have more to say about whether the zones actually create new business, or simply tempt existing factories and offices to move up the road to chase tax breaks.
On the Clydebank in Scotland, 117 companies moved into one zone, with 47 of them starting up for the first time. In Newcastle/Gateshead, all 36 companies in the local zone are thought to be new.
So far Britain has not followed the example of Singapore, Hong Kong, Hamburg, and Shannon, Ireland, in setting up ''free ports.'' Companies manufacturing within them are free from rates and taxes but must export all goods.
Trade unions have objected to community work projects, claiming those employed on them, at low government wages, keep other workers from earning normal rates for the same work. The government has compromised by raising the weekly wage to (STR)60 ($106) - well short of normal rates, but above the lower rates paid under earlier projects.