Wednesday, February 17, 2010


It is generally believed that labour accounts for about 2/3 of all income generated, and that capital accounts for approximately 1/3 of national income

as such, percentage-growth in potential national income is = to the percentage change in the level of technology + 2/3 * the percentage change in labour + 1/3 * the percentage change in capital


-It is impossible to directly measure technological change. Solow tried, and got a Nobel Prize.

-The Solow growth model included only 3 independent varaibles: labour, capital, and "other"

-This "other" is the "Solow Residual" or "Total Factor Productivity" or "A" (in our model). It captures all growth in GDP which is not accounted for by changed in N (L and H) and K.

-BIG PROBLEM HERE: Solow's model included both the quantity and quality of labour and capital, and a great deal of technological change is EMBODIED with labour or capital (so technology factors into labour or capital, and cannot always be separated them from). For instance, if one of my shitty sweat-shop sewing machines breaks down and I decide to replace it with an uber-fast, ultra-modern sewing machine, the capital stock will remain the same for my sweatshop, but the technology level has increased.

-As such, the Solow residual underestimates true technical change (as it can only include disembodied technological changes)


The Cobb-Douglas Aggregate Production Function is an example of an aggregate production function with 2 characteristics
-The law of diminishing marginal utility
-Constant returns to scale

For this APF, Y = A * N(2/3) * K(1/3)

Here, equal growth rates in labour and capital cause total GDP to grow at the same rate (as it would in a steady state)

y = A * k(1/3)

This is the per-capita APF, where y is per-capita GDP, and k is the capital-labour ratio
Equal growth rates in both labour and capital (ie: a constant k) cause y (per capita GDP) to remain constant


1: Increase savings (let per capita savings become larger)- in order for growth to occur, the economy requires sufficient savings to increase the capital stock faster than the population growth.

If you are in the Robert Gateman club of not-breeding, choosing NOT to personally contribute to population growth can also help economies grow here...

2: Increase technology: This requires infrastructural developments (health, education, law, physiological needs such as food and water taken care of), and many such developments are difficult for developing nations to set up.


Technological improvements lead to increased productivity, which increases the potential per-capita GDP

Embodied Technical Change = technical change intrinsic to the particular human or unit of physical capital in use: it is a change in the quality of the input (so a higher education, or a computer upgrade would both be examples of embodied technical changes)

Disembodied Technical Change = technical change that is NOT intrinsic to human or physical capital in use. This is a change other than to the quality of the capital (so if my sweat-shop fore-woman comes up with a fantastic new sewing procedure which halves the time it takes her to sew a sneakers, and then she teaches all of her sweat-shop buddies how to sew like this, that new technique would be an example of a disembodied technical change)

Usually, disembodied changes eventually become embodied, so the distinction becomes less important over the long run.

CONVERGENCE HYPOTHESIS: This an interesting theory, and there are 2 different facets of it

1: Absolute Convergence: the tendency for GDP AND Growth Rates in GDP to be equal across nations: each nation will have the same steady state values for y* and k*
-This assumes that different countries have the same marginal propensity to save, the same rate of population growth, and the same rate of technological improvement
-This theory states that if two countries have the same growth model, then even if one starts farther to the left, they will both end up with the same standard of living

2: Conditional Convergence: the tendency for Growth Rates in GDP to be equal across nations: each nation will have the same steady state values.
-This theory assumes different marginal propensities to save for different nations, different population growth rates, and different technological growth rates
-This theory acknowledges that different countries will have different per-capita GDP, but states that they will have THE SAME GROWTH RATES!



The Neoclassical Growth Model made growth dependent on exogenous variables such as population growth, the savings rate, and the rate of technological change.

Some new growth theories alter the 2 assumptions of the Neoclassical Model:
-Instead of technology as exogenous, they state that technological changes can be explained within the economic model
-Instead of having diminishing marginal returns, some new growth models suggest that the marginal product of capital is constant, or that there is even increasing marginal product of capital over time!


Endogenous growth is self-sustaining growth
In this theory, we assume constant marginal product of capital
For an example, if the price of an input rises, firms will develop a new technology rather than just switching to an existing alternative input (so market structures and competition can facilitate technological change)
-Some people believe that competition foster technological change: others believe, especially in the case of health technologies, that only monopolies can risk the large expenditure required to create new drugs

LEARNING BY DOING: In the 1940s, Shumpeter said that innovation was a one-way street- that research caused new developments, which led to new machines and new products. Today, things work different: it is more of a 2-way street. There is a feedback mechanism (ie: the Japanese method of building cars, where the mechanics and workers collaborate with the designer in order to streamline research and production in such a way that is productively efficient).

-Different countries respond to economic shocks in different ways. Some will find different countries to produce goods in where costs are cheaper: others will change production methods and increase technology to make it more cost effective!


INCREASING MARGINAL RETURNS TO INVESTMENT: Here, each new addition to the capital stock is more productive than the last.

There are 2 sources of increasing marginal returns to investment:

Market-Development Fixed Costs (Paul Romer)
-The original investment into new knowledge or technology has a large fixed cost
-Adopting or adapting this new technology once it has already been established is cheaper
-Also, consumers, wait to use new technologies
-In this way, the costs decrease as more and more people adopt new technologies, so the returns to scale increase with increasing investment

-It is a public good, so it is not subject to the law of diminishing marginal returns
-New ideas are non-excludable and non-rivalrous (as much as copyright laws try to prevent people from accessing them)
-New ideas are pure public goods
-New ideas may not suffer diminishing marginal returns
-SOOOO, because ideas play such a big role in economics, and ideas are practically unlimited, economics doesn't have to the be DISMAL SCIENCE! Yay!



-1970s, the club of Rome published a book called "Limits to Growth"
-This book predicted that increased growth would eventually destroy the earth's resources...

Here is their usual anti-growth argument: growth will look like more of what we witness today: production of mostly useless, impractical consumer goods with a short lifespan, which end up in the landfills in a couple of years.

This could be countered with the argument that growth can still occur, but under that condition that instead of producer large quantities of shitty goods, we focus on producing higher-quality, cleaner, longer-lasting, more efficient products.
-Growth permits societies to protect the environment and help the poor (if you haven't noticed, environmental protection legislation is more a by-product of mature industrial economies, and less-so of developing nations)
-The thought is that market participants will react to supply shortages, and innovate around them (ie: by the time oil runs out, productive processes will have innovated away from it)

-Limits to growth are based on fixed technology and resources
-BUT, technology leads to more efficient resource use
-AND technology leads to the discovery of new resources
-Problem: THERE ARE TOO MANY PEOPLE: More people on the earth means that we will require more resource expenditure

-Economic growth creates pollution. Nuff said

Although many economists believe that growth creates opportunities for humankind to combat resource depletion and pollution through increased technologies, a lot of these beliefs are based on blind faith.

Like... we are basically relying on our ability to innovate away from these problems...

but what if we simply can't do that? Then what..............?

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