Static analysis
Encyclopedia
Static analysis, static projection, and static scoring are terms for simplified analysis wherein the effect of an immediate change to a system is calculated without respect to the longer term response of the system to that change. Such analysis typically produces poor correlation to empirical results.
Its opposite, dynamic analysis
or dynamic scoring, is an attempt to take into account how the system is likely to respond to the change. One common use of these terms is budget policy in the United States, although it also occurs in many other statistical disputes.
theory. Starting with Thomas Malthus
at the end of the 18th century, various commentators have projected some short-term population growth trend for years into the future, resulting in the prediction that there would be disastrous overpopulation within a generation or two. Malthus himself essentially claimed that British society would collapse under the weight of overpopulation by 1850, while during the 1960s the book The Population Bomb
made similar dire predictions for the US by the 1980s.
Similarly, some scientists used a short-term trend of temperature declines during the 1930s to theorize that the world would be in an ice age
by 1978. As with the overpopulation theories, the projection was less accurate than a roll of the dice because it didn't take into account how factors interact, nor how a short-term trend was being treated like a long-term trend.
For economic policy discussions, predictions that assume no significant change of behavior in response to change in incentives are often termed static projection (and in the US Congressional Budget Office, "static scoring"). By contrast, dynamic scoring refers to projections based on historical response of population to the effect of economic policy changes such as tax increases or cuts.
Typically, static analysis works for very simple systems: for example, how fast snow is accumulating in what is thought to be the mid-point of a blizzard. But even then it must be tempered with rationality—guess how much longer the storm might actually last, rather than assuming that snow will fall continually for the next sixty years, and project the average of the storm so far, rather than plotting the curve of its growth as if that will continue to increase for the second half.
However, when applied to dynamically responsive systems, static analysis tends to produce results that are not only incorrect but opposite in direction to what was predicted, as shown in the following applications.
were explicit in their recognition of the apparent paradox that while static scoring would suggest a change in taxes will produce revenue change commensurate with the tax, in reality revenue tends to change in the opposite direction, due to the response of those affected.
The empirical evidence for this is available but not widely discussed. Several references, both from economic and political sources, draw on data demonstrating the difference between static scoring of a tax policy change, and the actual result.
as an instance of static analysis: accelerating change
in some factor of information growth, such as Moore's law
or computer intelligence, is projected into the future, resulting in exponential growth
or hyperbolic growth
(to a singularity), that suggest that everything will be known by a relatively early date.
s: After their invention, all safety razors were single-bladed for 70 years. Then the first double-bladed razor was introduced. It only required 15 years for a third blade to be added, and then one year for the fourth and fifth. Fitting these five data points to a hyperbolic curve produced the prediction that within nine years of the calculation—by the year 2015—safety razors would have an infinite number of blades.
Its opposite, dynamic analysis
Dynamic scoring
Dynamic scoring predicts the impact of fiscal policy changes by forecasting the effects of economic agents' reactions to policy. It is an adaptation of static scoring, the traditional method for analyzing policy changes....
or dynamic scoring, is an attempt to take into account how the system is likely to respond to the change. One common use of these terms is budget policy in the United States, although it also occurs in many other statistical disputes.
History
The term was used in 1977 in an international academic journal, in a discussion of tax policy. In recent years, it has become very common in academic, business and political discussions of US government economic policy.Examples
A famous example of static analysis comes from overpopulationOverpopulation
Overpopulation is a condition where an organism's numbers exceed the carrying capacity of its habitat. The term often refers to the relationship between the human population and its environment, the Earth...
theory. Starting with Thomas Malthus
Thomas Malthus
The Reverend Thomas Robert Malthus FRS was an English scholar, influential in political economy and demography. Malthus popularized the economic theory of rent....
at the end of the 18th century, various commentators have projected some short-term population growth trend for years into the future, resulting in the prediction that there would be disastrous overpopulation within a generation or two. Malthus himself essentially claimed that British society would collapse under the weight of overpopulation by 1850, while during the 1960s the book The Population Bomb
The Population Bomb
The Population Bomb was a best-selling book written by Paul R. Ehrlich and his wife, Anne Ehrlich , in 1968. It warned of the mass starvation of humans in the 1970s and 1980s due to overpopulation, as well as other major societal upheavals, and advocated immediate action to limit population growth...
made similar dire predictions for the US by the 1980s.
Similarly, some scientists used a short-term trend of temperature declines during the 1930s to theorize that the world would be in an ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
by 1978. As with the overpopulation theories, the projection was less accurate than a roll of the dice because it didn't take into account how factors interact, nor how a short-term trend was being treated like a long-term trend.
For economic policy discussions, predictions that assume no significant change of behavior in response to change in incentives are often termed static projection (and in the US Congressional Budget Office, "static scoring"). By contrast, dynamic scoring refers to projections based on historical response of population to the effect of economic policy changes such as tax increases or cuts.
Typically, static analysis works for very simple systems: for example, how fast snow is accumulating in what is thought to be the mid-point of a blizzard. But even then it must be tempered with rationality—guess how much longer the storm might actually last, rather than assuming that snow will fall continually for the next sixty years, and project the average of the storm so far, rather than plotting the curve of its growth as if that will continue to increase for the second half.
However, when applied to dynamically responsive systems, static analysis tends to produce results that are not only incorrect but opposite in direction to what was predicted, as shown in the following applications.
Economic Policy
Presidents from John F Kennedy to Ronald ReaganRonald Reagan
Ronald Wilson Reagan was the 40th President of the United States , the 33rd Governor of California and, prior to that, a radio, film and television actor....
were explicit in their recognition of the apparent paradox that while static scoring would suggest a change in taxes will produce revenue change commensurate with the tax, in reality revenue tends to change in the opposite direction, due to the response of those affected.
The empirical evidence for this is available but not widely discussed. Several references, both from economic and political sources, draw on data demonstrating the difference between static scoring of a tax policy change, and the actual result.
Technological singularity
Some have criticized the notion of a technological singularityTechnological singularity
Technological singularity refers to the hypothetical future emergence of greater-than-human intelligence through technological means. Since the capabilities of such an intelligence would be difficult for an unaided human mind to comprehend, the occurrence of a technological singularity is seen as...
as an instance of static analysis: accelerating change
Accelerating change
In futures studies and the history of technology, accelerating change is a perceived increase in the rate of technological progress throughout history, which may suggest faster and more profound change in the future...
in some factor of information growth, such as Moore's law
Moore's Law
Moore's law describes a long-term trend in the history of computing hardware: the number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every two years....
or computer intelligence, is projected into the future, resulting in exponential growth
Exponential growth
Exponential growth occurs when the growth rate of a mathematical function is proportional to the function's current value...
or hyperbolic growth
Hyperbolic growth
When a quantity grows towards a singularity under a finite variation it is said to undergo hyperbolic growth.More precisely, the reciprocal function 1/x has a hyperbola as a graph, and has a singularity at 0, meaning that the limit as x \to 0 is infinity: any similar graph is said to exhibit...
(to a singularity), that suggest that everything will be known by a relatively early date.
Satire: safety razors
A satire on this idea has been presented using the development of safety razorSafety razor
A safety razor is a razor that protects the skin from all but the very edge of the blade. These razors reduce the possibility of serious injury, which makes them more forgiving than a straight razor.-Cartridges introduced:...
s: After their invention, all safety razors were single-bladed for 70 years. Then the first double-bladed razor was introduced. It only required 15 years for a third blade to be added, and then one year for the fourth and fifth. Fitting these five data points to a hyperbolic curve produced the prediction that within nine years of the calculation—by the year 2015—safety razors would have an infinite number of blades.