201The following appeared in a memo¹ from the chief operating officer of the Presto² Manufacturing Company.

"Since orders for our major product increased by over 200 percent last quarter, we should promptly³ expand production by building a new manufacturing plant in Summit City. Summit City is the ideal location for the new plant because it has low property taxes, extensive blocks of land available for immediate⁴ purchase, and a large number of residents who are not currently employed."

202The following appeared in a memo from the president of a company that makes breakfast cereals.

"In a recent study, subjects who ate soybeans at least five times per week had significantly lower cholesterol⁵ levels than subjects who ate no soy products. By fortifying⁶ our Wheat-O cereal with soy protein, we can increase sales by appealing to additional consumers who are concerned about their health. This new version of Wheat-O should increase company profits and, at the same time, improve the health of our customers."

203The following appeared in a letter from the mayor of Tudor City.

"After a major airline chose Yorkville as its regional flight hub, the number of businesses in that city almost doubled and local tax revenue increased by 50 percent. In addition, as travel to Yorkville became easier, most respondents to a survey of the country's top executives identified Yorkville as a desirable place to transact⁷ business. To secure efficient transportation for Tudor City and stimulate⁸ our local economy, we should build a new airport, like the one in Yorkville, that is suitable for a regional flight hub."

204Blue City Highway had always been notorious for its tight curves and poor roadway visibility, and the accident rate there was generally very high. Last year the highway was redesigned to broaden the curves and improve roadway visibility. Drivers report that they now feel much safer driving on the highway and that the redesign has been a big improvement. But the number of accidents on the highway has not been significantly lower in the six months since the redesign than it was in the six months before the redesign. Therefore, the redesign clearly did not improve the curves and roadway visibility enough to make a difference.

205One kind of brain-scanning device is used by doctors to monitor normal as well as abnormal activity in a patient's brain. The device provides precise measurements of blood flow in the brain, a known indicator⁹ of how the brain is working. Unfortunately, the device requires patients to remain completely still with their heads in the scanning machine, which makes a very loud noise. Under these uncomfortable conditions, it is doubtful that doctors can get accurate measurements. A new head-mounted device that measures eye movements rather than blood flow and allows patients to move around will undoubtedly¹⁰ provide better brain measurements. Thus, the new head-mounted device should replace the older device at all hospitals and research institutions.

206The following appeared in a health newsletter.

"According to a recent study, people with many social ties report catching¹¹ colds less often than do people with few social ties. Consequently, researchers conclude that having an active social life probably helps strengthen the immune system. The researchers note that catching a cold — one of a family of highly contagious¹² viruses — gives the cold-sufferer temporary immunity¹³ to that virus in the future, but not to the many other related viruses. Merely being exposed to a new cold virus, however, is not enough for a person to catch a cold, since a strong immune system can successfully fight off some new viruses. Thus, in order to prevent catching a cold, people should strengthen their immune systems by becoming more active socially."

207The following editorial appeared in a newspaper in the country of Solaria.

"The Eliot Valley region was primarily agricultural twenty years ago. In the past twenty years, however, many computer-chip manufacturers have opened factories there. A recent study found that water pollution in the region was worse than in any other region in the country. Moreover, the computer-chip factories, which use large quantities of water to manufacture the chips, are probably responsible for the low levels of water in the region's lakes and reservoirs. Therefore, if the region's computer-chip makers¹⁴ had limits placed on the amount of water they could use, water quality would improve."

208The following appeared in an editorial in the Seatown newspaper.

"Seatown has a large port exclusively for fishing boats, whose owners pay fees for the upkeep of the docks and for facilities for cleaning engines and repairing nets. In recent years, declining fish populations have decreased fishing revenue and forced many owners to stop fishing altogether. As a result, the port has a high vacancy¹⁵ rate and port managers are considering allowing pleasure boats, including cruise ships and other large vessels¹⁶, to use the port in order to increase revenue. But allowing pleasure boats into the port would be a mistake, because the fishing boats would be forced out of the port. We should preserve the port for the fishing fleet, which, unlike pleasure boats, contributes to the prosperity of Seatown."

209The following appeared in a Brenton newspaper.

"The Brenton power plant draws water from Scott's River for its cooling system and releases the warmed water back into the river. The town council recommends that the plant install a more efficient cooling system that uses less water, claiming it will be more environmentally sound. However, in Uptown, where the new system is used, a study found that the complex network of pipes in the new system tends to accumulate algae¹⁷. The build up of algae can be avoided by scrubbing the pipes, which is costly¹⁸, or by adding an herbicide to the water in the pipes to prevent algae accumulation. But water containing the herbicide cannot be released back into the river and it is known that low water levels can harm river ecosystems¹⁹ accustomed to higher levels. Therefore, Brenton power plant should continue to use the old cooling system exclusively."

210The following appeared in a letter to the editor of the Maple²⁰ City newspaper.

"Twenty years ago Pine City established strict laws designed to limit the number of new buildings that could be constructed in the city. Since that time the average housing prices in Pine City have increased considerably²¹. Chestnut²² City, which is about the same size as Pine City, has over the past twenty years experienced an increase in average housing prices similar to Pine City, but Chestnut City never established any laws that limit new building construction. So it is clear that laws limiting new construction have no effect on average housing prices. So if Maple City were to establish strict laws that limit new building construction, these laws will have no effect on average housing prices."