Previous post snip
Unfortunately, this post lacks actual figures, so here's some to back this up, from the non-partisan CBO:
https://www.cbo.gov/sites/default/files/114th-congress-2015-2016/workingpaper/49925-FiscalMultiplier_1.pdfPage 11 has the range estimates for the so-called "Fiscal Multiplier" which is the term to look for if you want data on this sort of thing.
CBO expects that the economic effects of changes in fiscal policies are roughly symmetric, meaning that under similar economic
conditions the size of the fiscal multiplier is the same for stimulative polices (such as increases in government spending or
decreases in taxes) as for contractionary policies (such as decreases in government spending or increases in taxes).
In other words, raising taxes by $1.00 has the same contraction of the economy as the increase resulting from decreasing taxes by $1.00 (so these figures generally work for both talking about cutting or increasing functions, be they taxes or services).
Estimated Multipliers (a low end to high end range estimate)
low high
0.5 2.5 Purchases of Goods and Services by the Federal Government
0.4 2.2 Transfer Payments to State and Local Governments for Infrastructure
0.4 1.8 Transfer Payments to State and Local Governments for Other Purposes
0.4 2.1 Transfer Payments to Individuals
0.2 1.0 One-Time Payments to Retirees
0.3 1.5 Two-Year Tax Cuts for Lower- and Middle-Income People
0.1 0.6 One-Year Tax Cut for Higher-Income People
0.2 0.8 Extension of First-Time Homebuyer Credit
0.0 0.4 Corporate Tax Provisions Primarily Affecting Cash Flow
(on a side note, copy-paste broke the chart, so let me know if you see something I pasted into the wrong place)
What those Fiscal Multiplier numbers mean is how many dollars the economy increases or decreases as a result of these policies. These numbers are some of the most critical to good economic policy because it will tell you if you're doing the right thing for economic growth. Based on this chart, $1.00 of government spending on First-Time Homebuyer Credit results in $.20 to $.80 of economic growth. Which means your government's tax base has increased by less than the policy cost to enact, and so you don't really have a way to make your dollar back. Likewise, if you cut spending on this credit by $1.00, your economy would shrink by $.20 to $.80, but you would end up with a dollar to put elsewhere. This gives you the *true cost* of the policy, how much does it cost/benefit the economy, at which point you can start asking whether the societal benefits are worth the real cost.
Notably, many of these ranges are very large; and for good reason: building a bridge in an uninhabited forest won't grow your economy by much, but doing so in a city can. So there's still a lot of administrative wiggle room to make a policy a success or failure.
What's also notable is the multipliers for a lot of tax-related policies. $1.00 of tax cuts to the wealth grows your economy by only 10-60 cents. If paid for by reducing spending on infrastructure, that $.10-$.60 of growth comes at the cost of $0.40 to $2.20 of growth. (likewise by doing the opposite, you can get $.40 to $2.20 of growth at the expense of $.10 to $.60 of growth by building infrastructure and paying for it by increasing taxes on the wealthy). The other big one is corporate taxes -- increasing taxes on corporations simply hoarding money barely harms the economy but results in having more money available for allocating towards policies with a greater effect.
These numbers are very much a snapshot in time and place -- and will change based on government policies enacted. It's likely a highly non-linear space, but the government could at the very least attempt to maximize economic activity by doing a hill-climbing algorithm. Put money where it helps most, and take it from where it hurts least to get a stronger economy. These figures are pretty much the only justification for the government or its officials to talk about 'helping the economy' without being complete bullshitters.