Here are some scenarios for the Year 2000 problem, which I adapted from a posting in the Computer Risks Digest. As daily, weekly, monthly, and other periodically run programs encounter the problem, there is a constant drag on economic activities. Billions of dollars are spent correcting the problems. Everything done in 1999 that carries over to 2000 or done for the first time after 2000 will be problematic. Delays, errors, and decreased productivity diffuse through the economy.
Lawsuits proliferate, further dragging the economy down.
The effect is as significant as a major increase in tax rates or energy prices. The year 2000 problem results in a recession. In this scenario, as in the previous one, problems appear over time before and after the year 2000. Billions of dollars are spent correcting the problems, but some firms don't get them corrected and fail. Many programs run in 1999, which have, results that carry over to 2000 produce errors.