I would argue that the prolonged debate between well-educated and well-respected economists on the topic of government spending[1] indicates that reasoning alone does not lead to a single straightforward answer on the topic.
Since reasoning alone doesn't lead to an obvious answer on this topic, then I would argue that yes, you do need evidence to back up your claims.
> "do you think there's no limit to how much of other people's money governments can spend?"
It's obvious that there exists such a limit. However, the existence of that limit doesn't do anything to help us determine what amount of government spending is the most efficient.
The claim that:
1) There is a maximum amount of government spending possible
2) Therefore, the current government spending is too high
Has the same flaws as:
1) There is a maximum velocity that we can travel (c)
2) Therefore, the current highway speed limit is too high.
[1] For example, there were a large number of respected economists that weighed in on both sides of the 2009 American Recovery and Reinvestment Act
Well then, we can assume that all those economists have also presented evidence to support their cases, but even with evidence, they haven't reached an agreement. Therefore, it's pointless to demand evidence from me either.
You want to know what amount of government spending is the most "efficient", but you should first define what you mean with efficiency in that context.
In ordinary life, efficiency involves maximizing output from input, right? A car can be more fuel-efficient than the previous year's model, and so on.
So you want government spending to be "efficient", but all government spending represents a wasteful middle-man between people and their money and whatever goods and services they need. Therefore, all government spending is "inefficient" from the point of view of the people whose money governments spend.
So I'd say that there's no such thing as efficient government spending. What's efficient is people paying for stuff on a free market with free and unhindered competition among providers. Surely you know how competition works, and results in lower prices and higher quality, right? In other words, free competition results in maximal "efficiency" in an economy.
In conclusion, if you want maximal efficiency in the way money is spent, you can't support the idea of any government spending.
> "Well then, we can assume that all those economists have also presented evidence to support their cases, but even with evidence, they haven't reached an agreement. Therefore, it's pointless to demand evidence from me either."
The main difference being that evidence changes between 2009 and 2015. Maybe there is new evidence since then to really support your claim that I'm not aware of? Evidence is constantly changing. Raw reasoning and logic is not constantly changing. If the only basis we're working from is rational thought, then you should be able to reach the same conclusions that Aristotle did.
Hence, the request for evidence.
> 'You want to know what amount of government spending is the most "efficient", but you should first define what you mean with efficiency in that context.'
I'm sorry for assuming an economic context for my terms — elsewhere in the thread you asserted that "Opposition to UBI comes from people with a clue about economics" so I made the assumption that you were familiar with economic terms. Additionally, I'll be the first to admin that my economics background is merely some early econ classes in college and a general interest afterward. I'd be very interested to hear from any economics if I've badly mucked up any of these concepts.
> "In conclusion, if you want maximal efficiency in the way money is spent, you can't support the idea of any government spending."
I don't think there are many serious economists that you back you up on this assertion. This claims that I would be happier if there were no roads, no water supply, no education systems, no protection from criminals (which technically don't exist because there's no criminal behavior), and no protection from other countries. I absolutely would like some of my money taken and spent on those thing.
I'm happy to debate if the amount of government spending is currently too high or too low; I'm happy to discuss where the best place for it to be is. However, if you would seriously contend that the correct number is zero I think we may be too far apart on a base ideological level to continue this conversation in a productive way. At the very least arguing economics won't get us to any common ground — I think we'd have to switch over to philosophy before we'd find common ground.
> Raw reasoning and logic is not constantly changing.
That's exactly why it's a better foundation for economic conclusions.
Why would you keep requesting evidence even after acknowledging that there's evidence every which way? Anyone can just cherry-pick evidence that suits them, but where does that leave us?
Reasoning based on correct premises works pretty well though.
> I'm sorry for assuming an economic context for my terms — elsewhere in the thread you asserted that "Opposition to UBI comes from people with a clue about economics" so I made the assumption that you were familiar with economic terms.
Let's just say I've seen those terms thrown around, but they're vague and obtuse enough to be practically meaningless. That's hardly surprising, considering their main use is rationalizing government intervention.
For example, no economy can ever reach "pareto optimality": http://en.wikipedia.org/wiki/Pareto_optimality .. because every single voluntary exchange leaves both participants better off, because otherwise they wouldn't go through it. Since value is subjective, it really is enough that they both perceive a benefit in the trade.
If you want to argue against that, you'd have to somehow magically know how much I'd be willing to pay for a Ford Fiesta tomorrow at 4pm. But you can't. No one else can. Just like I couldn't possibly know your preferences at some given moment in time.
So yeah, pareto optimality is nonsense, as explained above, and so is a lot of the other stuff involved in these discussions. That's part of why I demanded definitions.
> I don't think there are many serious economists that you back you up on this assertion.
You'd have to look to the Austrian school of economic thought for that, but all of them would agree with me.
> This claims that I would be happier if there were no roads, no water supply, no education systems, no protection from criminals (which technically don't exist because there's no criminal behavior), and no protection from other countries.
All the services you list are provided by people working for a living. Do you want to claim people need governments to tell/force them to work for a living?
> I absolutely would like some of my money taken and spent on those thing.
No you don't. No one wants to be robbed, any more than beaten to a pulp with a baseball bat. What you might be thinking is that you're willing to pay for those services, but that would also apply without getting robbed.
> At the very least arguing economics won't get us to any common ground — I think we'd have to switch over to philosophy before we'd find common ground.
