Homes in the northeastern United States, where winters are typically cold, have traditionally used oil as their major fuel for heating. Last year that region experienced twenty days with below-average temperatures, and local weather forecasters throughout the region predict that this weather pattern will continue for several more years. Furthermore, many new homes have been built in this region during the past year. Because of these developments, we predict an increased demand for heating oil and recommend investment in Consolidated Industries, one of whose major business operations is the retail sale of home heating oil.
The argument claims that recently, very cold weather has been predominated. Besides, many new homes have built in the region. Therefore, the oil demand increment is probable and investment in consolidated industry is required. Stated in this way the argument fails to mention a lot of key factors on the basis of which, evaluation can be made. The conclusion of the argument relies on assumptions for which there is no clear evidence. Hence, the argument is not cogent, and suffers from several flaws.
First, the argument readily assumes that consequent years are similar to the previous one. This statement is a stretch and is not substantiated in any way. Because each year has its own conditions, and years are different in many aspects i.e. rainfall and snowfall quantity. Besides, an adequate equipment in order to guess the long-term weather pattern has not been invented yet. There are a lot of examples which show that this assumption is fallacious. In my country, Iran, ten years ago, we encountered an arid year, which made everything hard. We could not go out to accomplish our daily task. The weather was suffocating, and forecasters, subsequently, predicted that we would face a rather a drier condition for the following years. But, three months later, everything changed, weeks of the rainy weather, which was originated from the Indian ocean, energized plants and humankind, helped them to recover their losses and return to their ordinary life. Therefore, forecasters are not capable of estimating climate changes for more than a few weeks or months. In addition, the argument would have been clearer if it explicitly mentions solid evidences to reinforce this assumption.
The second flaw that crosses my mind is that the argument claims that based on the weather condition for just less than a month, the situation can be ascribed to the whole year and be extrapolated for the sequential years. This is again a very weak and unsupported claim as the argument does not mention any correlation between that 20 days and the whole year. To illustrate, it is possible that during that period of time, namely twenty days, oil consumption was increased. But, it was at a normal rate, even less than the standard quantity, for the rest of the year. In fact, the argument does not even mention morsel of information about other times. If such a correlation had been shown between different weather conditions, which supposedly work well, then the author would have sounded a bit more convincing. Besides, if the argument provides examples of similar phenomena during past years, the argument could have been strengthened even further.
Last but not least, the author mentions the word "MANY", in sentence many new homes..., which can be interpreted in different ways. It is not obvious what does he or she mean by the word many? From this statement, it is not at all clear how the author measures the influence of new homes on the oil consumption, and concludes that increment in demands is probable. It is possible that new homes use different energy sources to accomplish their household tasks. Without supporting explanations from official statistics, one is left with the impression that the claim is more of a wishful thinking rather than substantive evidences. As a result, this conclusion has not legs to stand on.
To sum up what I have outlined above, the argument is flawed and therefore unconvincing. It could be strengthened if the author mentioned all the relevant facts. In order to assess the merits of a certain situation, it is essential to consider all contributing factors. In this particular case, time dependency of weather, solid evidence in order to provide a provable correlation, and elaborate vague terms, are three main flaws which should be explained better. Without this information, the argument remains unsubstantiated and open to debate.