Each day, Laszlo Melenyecz arrives at his job as a project manager in an engineering firm by 7 a.m., early enough under the company's flextime system to free himself by midafternoon. The schedule is no mere convenience: After his early job, Melenyecz has just enough time to speed to another machine workshop and another supervisor's shift.

After four or five more hours of work, this 38-year-old electrician finally goes home to his family of three, exhausted from his two jobs but confident that his bills will be paid. "Physically, it's just really tough," he said of his routine. "It's bad for human relations, family relations, everything. But it's the only way to have a decent living standard."

Melenyecz's enterprise makes the difference between economic hardship and relative affluence in communist-ruled Hungary. Before taking a second job, he said, he could not pay his bills. Now, with his double duties and his wife's salary as an accountant, his family can afford a well-furnished apartment, two cars and luxury appliances. "I have a hi-fi, a video, everything," Melenyecz said. "Or, anyway, relatively everything."

While such hard-won prosperity may make Melenyecz an exception among Hungarians, his work at two jobs is not unusual. Driven by burgeoning material ambitions or sheer economic necessity, millions of people in this economically strapped nation are working double time, earning Hungary a reputation as perhaps the hardest working communist country in the world.

At least 210,000 urban workers and about 1.5 million rural families in this country of 10 million now work more than one regular job, and some economists estimate that as many as three families in every four earn at least some income from extra employment. Jobs in privately owned industry and trade, a frequent outlet for extra work, increased by 25 percent last year and now amount to more than 200,000, according to official statistics.

At Prizma, the state engineering and design cooperative where Melenyecz works first, half the 110 employes work a regular second shift and most of the rest have second jobs with other companies. "We encourage people to take up a second job somewhere else," said Dezso Forro, the firm's manager. "It means a higher salary for them, and it's good for Hungary."

The nationwide scramble for overtime has been an outgrowth of Hungary's pioneering effort to change the traditional socialist economic system by introducing such capitalist mechanisms as price competition, wages linked to productivity, and opportunities for some private enterprise.

Workers in other socialist countries have few opportunities to work outside state-controlled firms and few rewards for individual performance. But with scant natural resources and declining markets for trade, Hungary's planners believe that only increases in workers' productivity can resume growth stalled since the late 1970s and pay off the country's substantial foreign debts.

Incentives were first offered to rural families, who are encouraged to cultivate household plots in addition to their work in state cooperative farms and factories. Four years ago, industrial workers were offered the chance to form private "work associations" to do extra work in factories on a contract basis. Meanwhile, services, retailing and light manufacturing have been opened to private entrepreneurs.

Despite the popular rush for second jobs, the overall results of these policies have been mixed. Food and consumer goods are now abundant in Budapest's stores and services are markedly better than in other Soviet Bloc countries. But increases in productivity and efficiency have been below expectations, living standards have fallen rather than risen, and Hungary consistently has had one of the lowest growth rates in Eastern Europe during the past five years.

Some economists suspect that much of the country's hard work is being wasted. "All the factories work overtime, but it doesn't make up for their basic inefficiency," a diplomat said.

Many Hungarians are also concerned about how the new culture of overwork is changing society. Thousands of people, they say, work overtime not by choice or for extras but out of sheer necessity. The resultant pressure on families has helped give Hungary some of Europe's highest rates of alcoholism, heart disease and suicide, sociologists say.

The strains of daily life are depicted vividly in a film called "Countdown" that opened this month. The film, directed by Pal Erdos, tells the story of a truck driver who goes into private business and works 18-hour days to afford housing for his family. Eventually, he succeeds in buying a house, but has a heart attack that disables him. Then, still unable to retire, he takes up sewing work at home.

"Hungary is part of Europe, and we have certain expectations as consumers," said Erdos. "So we work 10 or 12 or 14 hours a day just to have our own homes and get consumer goods. But the end result of this is a warped consumer society. We've created conditions that are damaging human relations and weakening family ties, and that's very grave."

Erdos said he is now working on a film exploring the life of a man who wants only to work one job eight hours a day. "It is a normal expectation, after all," he said. "But in Hungary this road is not very hopeful."

Government officials concede that discontent among workers about living standards and working conditions is increasing. Yet, even when delegates to a trade union conference voiced rare criticism about social conditions last month, authorities simply repeated that Hungarians would have to work harder to improve conditions.

Then, too, many people appear grateful for the opportunity to do more after decades of state-controlled employment and uniform wages. At the Gobelin crafts cooperative in central Budapest, where nearly all of the 1,000 workers put in overtime or have second jobs, several young employes said they wished they could limit their work week to 40 hours.

But Gizella Szabo, 53, who has worked 34 years at the cooperative, said she welcomed the chance to work an extra 20 hours a week at home. The overtime has raised her income to more than 9,000 forints -- about $187 at the official exchange rate -- or about a quarter more than a typical Hungarian industrial wage, and Szabo has used the money to acquire a small weekend cottage in the country.

Next year, she will be eligible for a government pension. But she still plans to work 25 hours a week on contract for the cooperative, earning the annual maximum of about $1,230 that the government allows pensioners.

"Life is better in Hungary than in other socialist countries," Szabo said. "The shops are full, and we can afford to buy in them because we have the chance to work hard and earn it. The difference in Hungary is that it's not necessary to be poor, because if somebody wants to work hard and earn more they can do it. If somebody is poor, then that's their own fault."