If asked how much is a human life, alleviating human suffering, or a child’s well-being is worth, most of us would rightly wince at the thought of placing any monetary value on these. We are instinctively moved to devote whatever resources are necessary to protect even a single human life, ease human suffering, or help a child. This natural and appropriate human response, however, does not alleviate us of the moral responsibility for proper stewardship of finite resources. Resources are always finite. If we spend too much to save a particular life, we may consume resources that if more judiciously applied could save many lives. While it may be distasteful to assert that a life is worth a specific number of dollars, we can say that protecting many lives deserves a higher priority than saving one life. Sometimes dollars provide a convenient mechanism for computing the number of lives that may be saved. Using such an approach we often find that it is more efficient to apply resources to preventative care than enormous resources at the end of life that may add only a few days of life. The scary part is that if we move to a socialized health care system, we find that it is government rather than individuals who balancing resources against lives. This, however, is another story.
Here we suggest the necessity of performing a similar cost-benefits analysis on dealing with the prospect of climate change. As much as we might wish to anything possible to alleviate the effects of climate change, This is an approach recently suggested by the “skeptical environmentalist” Bjorn Lomborg. While we may wish to do whatever we can to reduce climate change and its effects, since resources are finite, reason compels us to ask how best to use these resources.
What are the costs of proceeding along the same course we are currently pursuing versus the costs of attempting to abate climate change? Of course the specific answer depends on who you ask and what part of the world you are concerned about. In a recent paper, “The Distributional Impact of Climate Change on Rich and Poor Countries,” published in Environmental and Development Economics, Robert Mendelsohn, Ariel Dinar, and Larry Williams attempt to bound the problem. They use the predictions of three climate models spanning the range of conventional predictions. The models predict a global increase in temperatures by 2100 ranging from 2.5 degrees C to 5.2 degrees C. The predicted precipitation changes range from a 15.5 increase to a 5.6% decrease. The increases in sea level range from 0.3 to 0.9 m. Local changes in different continents, though less certain, show far more variability.
The authors then couple the local climate change predictions with the local economies to determine the effect of climate on global and regional gross national product. On balance, the tropical countries, that are already warm, suffer the most. As one might expect, poorer countries, both because they tend to be nearer the equator and have a larger fraction of their GDPs linked to agriculture, suffer typically experience the largest negative impact.
Globally the effect of climate change on GDP by 2100, depending on both the climate and economic model ranges from a positive 0.10% to a negative 0.13%. Since the world economy will be substantially larger than by 2100, a 0.13% reduction will be a lot of money but the per capita effect would seem to be small, perhaps even a net positive. This would suggest that only we should accept only tiny changes on GDP as a cost of climate change reduction. This conclusion is especially true if we cannot eliminate, but only modestly reduce the effects of climate change. Of course, this calculus would be different for certain areas that would be more severely impacted.
Resources devoted to climate change abatement should also be balanced against other uses of the same resources, including providing clean water and medical resources to impoverished areas.
The work by Mendelsohn et al. is by no means a conclusive assessment of the economic effects of climate change and there is always the small but non-negligible possibility that climate change could be dramatically greater than the current best estimates. Nonetheless, the balance of the costs and benefits of climate change abatement against other possible uses of finite resources constitutes the only rational terms defining the debate.
Deadly Calculus
Sunday, October 21st, 2007It always difficult to examine death statistics, particularly statistics associated with the Iraq War. Every death represents the loss of someone’s spouse, sibling, or child. Treating these lives as numbers does not quite seem appropriate. However, we can often learn things by examining phenomena mathematically that are difficult to observe otherwise, and we should not dispense with any tool at our disposal. Indeed, epidemiology is the medical study of diseases in populations. Its use can often help discover was of dealing with disease. We only hope that the ideas presented here serve the same purpose.
The web site Iraqi Coalition Casualty Count provides the useful public service of compiling a day-by-day tally of Iraq Coalition casualties as well as the death of Iraqi security personnel and Iraqi civilians. It is perhaps most instructive to examine the monthly statistics. Month statistics are more reliable and they roughly mirror the evolution of the Iraqi conflict.
In the first month of the war, Coalition casualties were at their highest, averaging 7.67 deaths per day over the month. Then the casualty rates eased over the first summer of 2003, mostly averaging less than 2 deaths per day. During February 2004, the Coalition casualty rate actually dropped below 1 per day. Then the insurgency began in earnest, partially exacerbated by the bombing of an important Shite Shrine that inflamed sectarian tensions.
Sometimes, the casualty rate dropped below 2 per day, but for far too many months the death rate was well over 2 per day, sometimes even reaching over 4 per day. It is this relatively constant death rate with little sign of change, that has been the source of American frustration with the military strategy in Iraq.
Finally this year, the Americans under General David Patraeus, over the objections of many in Congress initiated a bold new initiative: the surge. With 30,000 additional troops, the surge represents an attempt to aggressively change the dynamics on the ground. By most accounts, at least from a military perspective, the surge seems to be working. Violence is down. The number of civilian deaths has dropped from over 3,000 a month early in the year to less than 1,000 per month in recent months.
Is this impression consistent with the accurately counted Coalition casualties? In May of this year, when the surge was beginning in earnest, the casualty rate was a high 4.23 deaths per day. One might have expected with more soldiers in the field taking a more aggressive posture that the number of casualties would, at least at the beginning of the surge, actually increase. However, since May there has been a steady drop in coalition casualties. As of this writing, for the current month, the casualty rate is 1.45 per day.
This drop is most impressive because it does not appear to be just a random good month. The casualty rate has been dropping over an extended period of time. Moreover, in only 14% of the months of the war has the casualty rate been this low. Many of those months were in the early period of the war.
If the casualty rate can show the same steady decline over the next few months, even with some set backs, the surge strategy will be unequivocally successful. If the casualty rates drop below the 1 per day rate for an extended period of time, Americans will become optimistic about the prospects for victory. There will probably never be a clear moment of victory in Iraq, but if the violence continues to abate, the Iraqis and Americans will slowly slip into victory.
Posted in Social Commentary | No Comments »