21.      
　　 The conclusion of this editorial is that the government should lower property taxes for railroad companies. The first reason given is that railroads spend billions per year maintaining and upgrading their facilities. The second reason is that shipping¹ goods by rail is cost-effective and environmentally sound. This argument is unconvincing for several reasons.

      First of alt, the argument depends upon a misleading comparison between railroad and truck company expenditures². Although trucking companies do not pay property tax on roads they use, they do pay such taxes on the yards, warehouses³ and maintenance facilities they own. And while trucking companies pay only a portion of road maintenance costs, this is because they are not sole users of public roads. Railroad companies shoulder the entire burden of maintenance and taxes on their own facilities and tracks; but they distribute these costs to other users through usage fees.

      In addition, the author assumes that property taxes should be structured to provide incentives⁴ for cost-effective and environmentally beneficial business practices. This assumption is questionable⁵ because property taxes are normally structured to reflect the value of property. Moreover, the author seems to think that cost-effectiveness and environmental soundness are equally relevant to the question of tax relief. However, these are separate considerations. The environmental soundness of a practice might be relevant in determining tax structuring, but society does not compensate⁶ a business for its cost-efficiency.

      Splitting the issues of cost-efficiency and environmental impact highlights an ambiguity⁷ in the claim that railway shipping is more appropriate. On the one hand, it may be appropriate, or prudent⁸, for me to ship furniture by rail because it is cost-effective; on the other hand, it might be appropriate, or socially correct, to encourage more railway shipping because it is environmentally sound. The argument thus trades on an equivocation⁹ between social correctness on the one hand, and personal or business prudence¹⁰ on the other.

      In sum, this argument is a confusion of weak comparisons, mixed issues and equivocal claims. I would not accept the conclusion without first determining: (1) the factors relevant to tax structure, (2) whether specific tax benefits should accrue¹¹ to property as well as to income and capital gains taxes, (3) whether railway shipping  really does provide greater social benefits, and (4) whether it is correct to motivate more railway shipping on this basis.
22.       
　　The conclusion in this argument is that increased vigilance by drug enforcement authorities has resulted in an increase in the illegal use of cocaine¹². The author reaches this conclusion on the grounds that drug traffickers have responded to increased enforcement efforts by switching from bulkier and riskier¹³ drugs to cocaine. Presumably, the author's reasoning is that the increased enforcement efforts inadvertently brought about an increase in the supply of cocaine which, in turn,brought about the observed increase in the illegal use of cocaine. This line of reasoning is problematic in two important respects.

      In the first place, the author has engaged in "after this, therefore because of this" reasoning. The only reason offered for believing that the increased vigilance caused the increase in cocaine use is the fact that the former preceded the latter. No additional evidence linking the two events is offered in the argument, thus leaving open the possibility that the two events are not causally related but merely correlated. This in turn eaves open the possibility that factors other than the one cited are responsible for the increase in cocaine use.

      In the second place, the author assumes that an increase in the supply of cocaine is sufficient to bring about an increase in its use. While this is a tempting¹⁴ assumption, it is a problematic one. The presumption¹⁵ required to substantiate¹⁶ this view is that drug users are not particular about which drugs they use, so that if marijuana and heroin¹⁷ are not available, they will switch to whatever drug is available—cocaine in this case. The assumption does not seem reasonable on its face. Marijuana, heroin, and cocaine are not alike in their effects on users; nor are they alike in the manner in which they are ingested or in their addictive¹⁸ properties. The view that drug users' choice of drugs is simply a function of supply overlooks these important differences.

      In conclusion, the author has failed to establish a causal link between increased enforcement efforts and the observed increase in illegal cocaine use. While the enforcement activities may have been a contributing factor, to show a clear causal connection the author must examine and rule out various other factors.