One of the greatest debates in history was whether or not too many people is a bad thing. Ireland of the 18th century was almost the very focal point of discussion while Malthus and Ricardo were formulating their ground breaking hypotheses. We are all fairly familiar with the all together appalling conditions of most of Ireland during this time period. The Malthusian belief held that Irish subsistence existence was a function of too many Irish. David Ricardo was quoted as saying “the land in Ireland is infinitely more populated than in England; and to give full effect to natural resources of the country a great part of the population should be swept from the soil”. Many held the belief that there being so little land per person, low levels of production per capita had produced a subsistence standard of living and the land had been so subdivided that these multiple independent farms were not economically viable. Too many people were causing poverty and preventing economies of scale. While Malthus’ view was the dominant view held among the social and political elite, other views existed. George Poulett Scrope, a contemporary of Malthus, believed that overpopulation was not the cause of Irish woes. Problems rather originated from centuries of turbulence and government mismanagement of Irish economic resources and affairs. In Belgium, experience with subdivided farms and agricultural division had consistently higher levels of output thus attempting to put to rest the loss of economies of scale in Ireland. Alas the debate raged, but it raged on in an empirical vacuum, until comparatively recently.
The Malthusian model consists of two equations and an identity. The first one relates the income per capita to the nonhuman to wealth ratio and the second one relates the rate of growth of labor to economic variables like income, opportunities of non agricultural employment or the diffusion of labor intensive crops such as the potato. And lastly the identity relates the present size of the population to past values of population growth. To examine the first equation, Joel Mokyr regressed the income per capita for the productivity of labor on the land/ labor ratio and other independent values that may influence income. If the Malthusian view was correct there should be a positive coefficient on the land labor ratio denoting that the greater the ratio or the difference between land and labor the more income. The second equation was examined by using the “propensity to marry” or the “demand for marriage.” Evidence showed that in a non-contraceptive society, such as 18th century Ireland, the crude birth rate was heavily affected by the average marriage age of the population. To illustrate that relationship he controlled for the “price of marriage,” using anything from nonagricultural employment to say the price of the potato.
Mokyr used the 1841 census and an OLS regression to examine the Malthusian theory. For the first equation, the land/ labor ratio was found to be consistently negative. The less land per person actually suggested more income. According to Malthus, the more densely populated the area the lower the income should be. The next set of results for the second equation was a bit ambiguous suggesting that the relationship between the rate of growth and economic variables was a bit more complex.
Overpopulation is an age old problem. Debates have raged over too many people as an undesirable situation. Malthusian views have theorized that overpopulation will result in wide spread poverty as productivity is strained to provide adequate levels of existence. Given Mokyr’s statistical analysis, poverty may not be an outcome of overpopulation. Other theories give rise to overpopulation maintaining its primary effects in the form of negative externalities on the environment. It is our ability to supply resources that drive exponentially expanding populations and ultimately greater demand. Eventually, some believe, we will reach a ceiling where the world simply can not sustain any more people no matter our ingenuity. The goal of this paper is to explicitly look at the effect of over population, examine the debate surrounding over population and finally offer up solutions for an issue that has been at the forefront at the very least since Malthus walked the earth.
What exactly is overpopulation? In Ian Sample’s words, overpopulation is when an organism exceeds the carrying capacity of its habitat. By 2150 the human population is forecasted to be in the realm of somewhere between 8 and 10 billion people worldwide. In the last forty years more people have been added to the population than in all previously recorded history. Accompanying this explosion in population is a rapid increase in urbanization where twenty to thirty million are annually migrating from rural areas. More importantly, a trend ever since the sixties, urban regions are consuming at levels three to four times faster than the rate of growth of people. Forty six acres of prime farmland per hour are paved to feed the burgeoning urbanization. Overpopulation is not a magic number where x amount of people is too many. It is more complicated in that it is the size and structure of that population in respect to the ability to supply and feed that population. As a consequence of our ever growing population, it is becoming exponentially more difficult to sustain.
Mankind has an insatiable appetite for resources. Almost 40% of farmland is seriously degraded, soil erosion exceeds soil formation and populations still need 26 million additional tons of grain per year to feed it. Urban sprawl, agricultural settlements and inefficient farming practices, all spurred by overpopulation, are responsible for half the world’s tropical forests having been destroyed and in the next two years as much as three quarters could be removed. Since the 1950’s, logging is up 3 fold and expected to double in the next fifteen years. Wood is demanded for building materials, cattle ranching and paper. Despite the growth in electronic media, paper use is up six times and “words printed” is doubling every ten years. To satisfy energy demands, free flowing rivers have virtually ceased to exist outside of the Mississippi and a few others. The Columbia river now exists as a set of 75 dammed lakes. To satisfy our appetite for fish alone, 25% of all fish consumed is now farmed. The ocean environment can not sustain such levels of consumption for the once bountiful harvest of Salmon in the 1920’s exhibited 240 million pounds of fish per year, today that number has dropped to 10 million. Despite developed world’s populations slowing in growth, consumption is not. It is increasing and as a result it is becoming more difficult to sustain fewer amounts of people.
For my own analysis, I have created a model that looks at air pollution, in parts per million, as my dependent variable. My independents were population density, GDP per capita and percentage of the labor force in industry and service sectors. I chose air pollution as an example of one form of externality of population. Given that overpopulation is beyond some number of people but rather that number and the ability of the local environment to sustain it, I chose population densities to more accurately reflect “too many people.” GDP per capita was chosen to control for the differences between more and less developed nations. Industry and service industries were selected to control for any extra polluters that may bias the sample. A country is theoretically going to pollute more if they have larger industrial bases. Given these variables, I ran a simple OLS regression.
Regression Output
Regression Statistics F Significance F 9.29 0.00
R Square 0.18
Adjusted R Square 0.16
Standard Error 35.86
Observations 174
Coefficient Standard Error t Stat P-value
Intercept 84.43 17.72 4.76 0.00
Pop Density 0.004 0.002 2.18 0.030
GDP Per Capita -0.0009 0.0002 -3.12 0.002
Industry % 0.22 0.25 0.88 0.37
Service % -0.46 0.25 -1.78 0.076
From the model above we can see that population density in increase carries with it a slight increase in pollution parts per million. However, the percentage of a market that has undergone a tranformation from industrial to service maintains the strongest negative effect on pollution. Developed economies such as OECD nations that have industrialized and developed to service oriented nations tend to pollute less than those that haven't. Some literature lends itself to illustrating that the wealthier an economy the more they can "care" to clean up after themselves. In reality and according to this model, caring seems to be irrelevent. Rather the natural development and adaptation of an economy is geared to inherently pollute less, in terms of air pollution. Further testing of a wide variety of elements ranging from deforestation to to chemical waste and so on would be necessay to examine this trend more effectively and help lend evidence to whether or not population progressions and industrializations ultimately curb environmental impact and resource consumption. However, it is clear that there is a positive correlating relationship with with population densities and air pollution. While the effect may not be overly large, an increase in population densities corresponds with an increase in air pollution. It does illustrate one form of negative externalities that population carries with it.
The overpopulation problem may be seen as straight forward but because of the complexities, both physical and political, surrounding the issues even open discussion is a bit thorny and fiery at times. It is fairly obvious that we consume large amounts of resources and factions exist as to whether or not such consumption is harmful. Beyond that, if all sides agreed, because of the physical, political and self interested factors solving the issue can be difficult, almost bordering impossible.
Consciousness of the interrelatedness of various elements in the global system has provoked examination and more importantly understanding of population’s effect on the environment or rather the “population problem” . As of today there are primarily three view points on the topic at hand, everything is fine, everything is terrible and finally there are some who are just in the middle. Some see the explosion in growth as the greatest harm that could come to the planet despite our ability to educate and technologically advance to minimize our footprint on the world . Eventually we will reach a point where population is flat out unsustainable. The other extreme of the debate feels that human ingenuity is not given enough credit. People can essentially always develop newer technology that can sustain any level of human population. And lastly, those in the middle of the debate feel there are intervening political, social, economic and technological factors that are playing a role and may indeed be, at least in the short run, easier to modify than the world’s population growth rate. The two extremes are often too simple while, the third position really illustrates the tone with which any approach to the issues must be taken.
One cannot just simply say x amount of people is too many. Populations consist of stocks and flows where size, distribution, composition and structure are as important as migration, fertility and mortality. It must also be considered the primary and secondary elements that sustain populations . Primary meaning raw materials and resources like air water and energy. Secondary includes built, non-built and uninhabited environments. A desert environment may not sustain a population like New York City. Lastly there are the different scales of pollution that the population problem can create ranging from the local level to the region national and international one. At the local level primary consequences consist largely of industrial waste, city pollution and soil erosion. Beyond the local level into the regional, national and international, consequences broadly include acid rain, CO2 and rising sea levels. Given this jurisdiction drawn in the sand, it is very difficult to communicate the consequences of a regional level to a local one. The city of Tampa does not overly care about acid rain in South Florida. And the complexities do not end there, whenever a physically difficult situation arises; people like to interject politics as if it is some sort of solution.
The political overtones of the population problem are almost as complex as the understanding of overpopulation itself. There is a political war afoot between the more and less developed countries (MDC’s and LDC’s) of the world. The LDC’s feel that they are being unfairly targeted given their population growth rates . They account for three quarters of the world’s population yet 90% of the world’s population growth takes place in the less developed world . LDC’s feel their population does not mean as much given that the developed world accounts for the bulk of consumption and CO2 output. MDC’s over fish drain resources and contribute to acid rain. However it has to be understood that LDC’s care more for development than they do for degradation, yet the former causes the latter. Maybe it is important that the less developed part of the world takes into account both to minimize the impact there future impact environmentally.
If the political and physical challenges could be overcome, what could solutions to environmental degradation look like? How can we minimize the externalities of overpopulation? Possibilities are vast, ranging from internalization through taxes and the free market to physical population controls. Ansley Coale sees education and accessible clinics to ease population stress while Ronald Coase has opted for property rights as a means to negate market failure. Both may or may not be viable yet if the solutions are going to be found they both help provide that starting place.
To put it plainly the world needs to internalize the externalities of overpopulation, it may be easier said than done. One idea, not very practical, is to force users of free flowing water to discharge their water upstream. A practical derivative would be to regulate production to use recycled air and water. Solutions also rest in the greater use of Pigouvian taxation. For instance, a factory that pollutes x amount should be taxed the amount it costs to clean up that x amount. Interestingly, the Coase theorem its most fundamental form states that greater definition and enforcement of property rights will force individuals and firms to internalize their own externalities. For instance, a factory dumping waste in a river where fishermen operate, if the factory owns the river, fishermen will pay the factory to clean them self up and if the fishermen own the river the factory will pay them to dump waste in the river. In reality the theory is not quite as applicable for it unrealisticly hinges on zero transaction costs. Zero transaction costs are few and far between, however the theory is not completely useless. A semi Coasian approach finds the development of resource markets a more practical approach to the issues of externalities.
Approaching the issue of air pollution, some have taken a semi Coasian approach of using what is called a cap and trade model. Strict limits are set on the amount of emissions allowed for said industry. The factories or sources covered by the program are granted permission in the form of permits to pollute within the cap. From there the individual firms can form their own compliance strategy based on buying more permits or selling their excess. An incentive is created to pollute less because of the profit motive linked to buying and selling pollution these pollution permits.
Ansley Coale’s specific alarm lies in the fact that the population growth rate is exceedingly large. The United States, who maintains relatively small rates of growth, is doubling the population every sixty years. The connection between growth and degradation is fairly clear, therefore Coale’s more controversial solution is to make sure that each and every birth is a deliberate choice. As far back as 1970, nearly a fifth of US births were classified as “unwanted”. To mitigate population, he sees education and clinical accessibility as reining in growth rates and coinciding environmental degradation. Ronald Munson, in a response letter to Coale’s work, pointed out that the reduction in population through easy access abortions may be insufficient as immigrant arrivals exponentially exceed departures. In other words, before any policy is proposed to reduce births, policy must come to grips with immigration before such an idea is posed and considered.
Population maintains externalities. Whether it is pollution, soil degradation or deforestation, exponentially increasing populations wrought exponentially increasing strain on the environment. The argument is a dynamic one that is difficult to address and even harder to solve. However solutions exist. Ronald Coase was revolutionary with his property rights solutions, however he was also impractical. That idea spawned other ideas such as the “Semi Coasian” air market. Some economists find solutions in population control and others see a greater use of Pigouvian taxation. Ultimately, overpopulation is an issue but given our own ingenuity it may be solvable. Not so much in the sense that mankind will think through better solutions that ultimately exacerbate overpopulation, but rather a means of curbing our own growth.
Human population stabilisation
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Originally Posted by Trax
http://www.twcenter.net/forums/showthread.php?470432-BunnyPoopCereal-s-Workshop-FTW
if you are having more kids than you can feed and clothe, let alone house and educate. You bring too many children into the world and their only destiny is a short life of suffering.
