Economies of Scale and the Great Merger Wave
Summary of the article
The author of the article doubts the claims that reaping of economics of scale caused the great merger wave of 1898-1902 and argues that the more important increase in size and quality among factories happened earlier. The author supports his words with the various data and compares it against that of his opponents. O’Brien compares the opinion that the merger wave was intentionally aimed to suppress competition and prices against the opposite opinion, according to which the merger wave was a natural structural response to the stress experienced by previously unexploited economies of scale (639). 
Analysis of the article  
I find O’Brien’s article rather successful in bringing the readers to the same conclusions he made himself with the help of the data and theories of other researchers. O’Brien enlightened both views providing supportive information for both. By doing this the author demonstrated that he is aware of the possible counterarguments and that he has studied and evaluated them too. This contributes very well to the convincing power of the work.
I strongly support the author’s central argument that the merger wave of 1898-1902 was caused by the wish of large factories to control market and importantly the prices for their products (p. 639). This opinion of mine is based on initial personal knowledge and logical suggestions, which were further supported by the facts provided by O’Brien, such as the evidence that factories’ size growth ended by the time the merger wave was proclaimed, and the other fact that nearly half of the mergers of that period eventually failed financially (pp. 639 – 640). Moreover the author also reminds that there were such positive aspects as technological growth and management innovations in 1870s and 80s, which prove that the merger wave of 1898-1902 could not be caused by unreaped economies of scale (p. 646). The counterargument provided in the text argues that the trend was a natural response to structural evolution and that it was the optimal organizational form at that time, which positively influenced many spheres. These arguments are indeed rather weak.
What I found rather shocking was the senseless opinion of the economists who were supporting the idea that great merger wave was a natural, positive and beneficial trend (p. 642). Since the mergers were aimed on reaching the oligopolistic structure of the market, it meant that they wanted to dominate without giving a chance to smaller competitors. This was simply not going along with the idea of encouraging entrepreneurship and American democracy, which concerned economic sphere as well. Moreover, oligopoly could not provide quality products over the long period of time just because the dominating companies would not be challenged by other competitors. Thus I do not understand why O’Brien did not point this out while presenting Brozen’s point of view (p. 642). I also disagree that average level of employment can be a reliable measuring standard for the size of the factories of that time. My reason for that is the fact that number of employees was not always necessarily equally related to the amount of their production output and the size of the factory, it could mean simply little use of labor-saving technology. Even though O’Brien suggests focusing on the period when employment rates did not grow much, I would still fear the same confusion, moreover, the census data from different years was reflecting different aspects, which would contribute to the mistaken conclusions (p. 644).  Although I do not completely agree with the method of measuring factories’ sizes, I agree with the research results and conclusions of the author, who states that important size growth was during the 70s and 80s and occurred due to technology and other innovations.
Conclusion
O’Brien did overall a good job in convincing his readers, based on wide and effectively applied research, that importance, motives and positive effect earlier acknowledged for the great merger wave of 1898 – 1902 is highly exaggerated and idealized, whereas the historical importance of industrial, technological and structural transformations of 1970s and 80s are neglected. O’Brien has presented strong enough argument that should be followed by further research with a better measuring approach, which would provide for more accurate conclusions.   
Bibliography
O'Brien, Antony Patrick. 1988. Factory size, economies of scale, and the great merger wave of 1898-1902. The Journal of Economic History 48 (3): 639-649.