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Economic Models - Convex Optimization

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The Advantages of Fiscal Leadership in an Economy 83<br />

re-distributive purposes only, but permitted discretionary expenditures for<br />

enhancing output.We further assumed that there were two types of agents —<br />

rich and poor — and that only the rich use their savings to buy government<br />

bonds. Based on this view, b would be the proportion of pre-tax income<br />

(output) going to the rich and s, the proportion of after-tax income that the<br />

rich allocate to saving. Tax revenues, τ t , can then be used by the government<br />

to re-distribute income from the rich to poor, either directly or via public<br />

services. This structure, therefore, has output-enhancing expenditures g t ,<br />

and discretionary transfers τ t . Both are financed by aggregate tax revenues;<br />

that is, from discretionary and trend revenues. Expenditures above these<br />

revenues must be financed by the sale of bonds.<br />

5.2. An Alternative Interpretation<br />

We could, however, take a completely different interpretation of Eq. (5).<br />

We could take the term s(by t − τ t ) to be the proportion of the budget-deficit<br />

ratio, as it currently exists, adjusted for the effect of growth on this ratio<br />

and any discretionary taxes raised in this period, which the government<br />

now proposes to spend in period t. The deficit ratio itself is of course<br />

d = (G − T)/Y = (e − r), where G and T are the absolute levels of<br />

government spending and tax revenues, and e and r are their counterparts as<br />

a proportion of Y. If the economy grows, then d = (G−T)/Y −ẏ(e−r)<br />

where ẏ denotes the growth rate in national income. If we wish to see what<br />

would happen to this deficit ratio if fiscal policies were not changed, it<br />

means new spending can only be allowed to take place out of new revenues<br />

generated by growth: G = T = rY. Inserting this, we have d =<br />

−(e − r)ẏ =−dẏ. Since y t is the deviation of Y from its steady-state<br />

path, by t in Eq. (5) will equal d, the change in the existing deficit ratio<br />

under existing expenditure plans and tax codes, if b =−(e − r)/Y 1 . The<br />

government will spend some proportion of that, s, less new discretionary<br />

taxes in the current period. Hence, s would typically equal 1, although it<br />

might be less, if some parts were saved in social security funds or other<br />

assets. This defines what would happen to the deficit ratio if there were no<br />

change in existing fiscal policies; but the term in τ t shows that governments<br />

may also raise additional taxes in order to reduce the current deficit ratio<br />

to some desired target value, θ, say. This target is likely to be θ = 0, to<br />

balance the budget over the cycle, as required by the stability pact. We give<br />

governments such a target, in the form of either a soft or a hard rule, in the<br />

objective functions that are discussed in Section 5.

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