Comment by c-linkage | Hacker News Reader

Comment by c-linkage | Hacker News Reader

I've always disliked economics because it never seems to make much sense. The first equation in the article -- the basis on which the entire premise rests -- just feels wrong.

> Spending is either on the consumption of goods and services or investment spending on equipment, structures, and intellectual property products. Income is allocated to either consumption or to saving by households, businesses, and government. In a closed economy, spending equals income—that is, the sum of consumption and saving equals the sum of consumption and investment spending.

> Spending (Consumption + Investment Spending) = Income (Consumption + Saving)

> Because consumption drops out on both sides of the equation, investment spending equals domestic saving in the economy. This makes sense: the funds available to invest in productive projects have to come from domestic savers.

It _doesn't_ make sense. How is consumption on the income side of the equation? And even if that somehow did make sense, who is to say the consumption on the income side is the same as the consumption on the spending side such that they balance out?

Saving is deferred spending, meaning money is set aside temporarily. One might think of this like a "cash queue" where the velocity of money slows down for a while. Is the assumption that all saving takes place in banks where banks can lend it out? If I stuff cash in a mattress (saving), how can that cash be used for investing?

A more realistic version might look like this:

                (fast)
  Income --+--------------+-> Spending --+--> Consumption
     ^     |              |              |
     |     +--> Saving >--+              |
     |          (slow)                   |
     |                                   v
     +---------------------- Investment and Production

This model involves time, but apparently economists only like models that incorporate addition and subtraction.

EDIT: If I'm asking questions, saying I don't understand, and offering a counter-model, doesn't that count as adding to the discussion? If I'm operating under some misunderstanding, there are certainly others who have the same misunderstanding but didn't speak up.

> It _doesn't_ make sense. How is consumption on the income side of the equation? And even if that somehow did make sense, who is to say the consumption on the income side is the same as the consumption on the spending side such that they balance out?

The model they are using is a simplified macroeconomic model. In their model, they are simply saying that when you account for Income--the total amount of money earned across the entire economy--it can only fall into two mutually exclusive buckets. Either the income is related to Consumption (purchasing goods and services), or Saving (as you mention, deferred spending--money in banks, or surpluses in the budget for states etc.--anything that is not in the consumption bucket).

> who is to say the consumption on the income side is the same as the consumption on the spending side such that they balance out?

By definition, it has to be. The way national income accounting works is that you can look at things from the perspective of expenditures or income. Since GDP is total output and total income, the total amount of consumption is the same, which is why it drops out in the equation from their model.

So in this simplified model, consumption is like a mobius strip in that while the mobius strip only has one side, income can only come from the consumption from spending.

The fact that they included it on both sides of the equation seems pointless, then, and only serves to confuse.

Klitgaard is talking about accounting, ie, instantaneous currency exchanges where, by definition, the gain on one side of the exchange has to equal the outlay on the other. Your model doesn't look like an accounting model; I suspect you want to talk about something different from what he is talking about - and that you want to talk bout policy implications rather than truisms (which is a good instinct; just not what economists care about when they sit down to talk accounting identities).

> How is consumption on the income side of the equation?

Isn't it just that one person's spending on consumption is another person's income from that consumption?

So what's negative savings in this model? Money you get temporarily and use to increase income?

> I've always disliked economics because it never seems to make much sense. The first equation in the article -- the basis on which the entire premise rests -- just feels wrong.

That's because you're reading an econ 101 equation, similarly how basic physics blogs use spherical cows in equations to simplify them. Most of internet (and even media) discourse about economcs never grows out of this level - it's like having people debate physics of nuclear reactors while their knowledge is stuck on Newtonian level.

Or, as some academic once put it - first year in economics college you learn econ101... and the rest of the years you're taught all the ways that model doesn't apply to real life.

Economics is the formalisation of confusing stocks for flows.

In the real world approximately zero saving occurs by stuffing cash in the mattress, so “all saving is investment” is a correct simplification.

Other people's consumption is your income, not production, producing does not generate income by itself.

It isn't called "the dismal science" for nothing.

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