I’m coming at this from two angles at once, so my points are a touch scattered.
1) The basic math. This says that putting money in as you get it is the best way to invest, because the market goes up over time, and that dominates any gains from DCA or market timing. When investing a lump sum there’s a small reduction in risk from DCA, but not enough to make it worthwhile in general.
2) The fact that I advise middle-class people on how to invest, and that this advice needs to be built primarily on psychology and not math. DCA is a good strategy for increasing real-world investment returns for normal people, because it convinces them that a down market is not the end of the world, and in some cases it convinces them to save at all(which far too many don’t, whether out of fear or short-sighted spending goals). Also, normal people tend to invest a portion of their paycheques, and that is a payment stream that leads naturally to DCA, even if the ostensible benefits of DCA don’t materialize.
The basic math. This says that putting money in as you get it is the best way to invest
I am sorry, “the basic math” says no such thing. It’s your strong assumptions (“the markets always go up”) which say this, assumptions I don’t consider to be self-evident.
primarily on psychology and not math
It would be helpful to clearly distinguish what you believe is the true state of the world (“math”) and what you think not-quite-rational people need to be told in order to do what you want to make them do (“psychology”).
I do not assume that “the markets always go up”. I merely claim that historically, the market has generally gone up faster than cash over the long run. This was the whole point of the paper linked above that said lump-sum beats DCA, and the same is true when investing a steady stream of income—you will generally do better in the market, so to maximize EV, invest right away when you get the money.
The post above was an attempt to draw that distinction. Are there any points I wasn’t sufficiently clear about?
That is not true. You advise your clients to act a way which implies a specific forecast: that the “markets” will, in the future, outperform other assets, e.g. cash, over the relevant holding period.
I’m coming at this from two angles at once, so my points are a touch scattered.
1) The basic math. This says that putting money in as you get it is the best way to invest, because the market goes up over time, and that dominates any gains from DCA or market timing. When investing a lump sum there’s a small reduction in risk from DCA, but not enough to make it worthwhile in general.
2) The fact that I advise middle-class people on how to invest, and that this advice needs to be built primarily on psychology and not math. DCA is a good strategy for increasing real-world investment returns for normal people, because it convinces them that a down market is not the end of the world, and in some cases it convinces them to save at all(which far too many don’t, whether out of fear or short-sighted spending goals). Also, normal people tend to invest a portion of their paycheques, and that is a payment stream that leads naturally to DCA, even if the ostensible benefits of DCA don’t materialize.
I am sorry, “the basic math” says no such thing. It’s your strong assumptions (“the markets always go up”) which say this, assumptions I don’t consider to be self-evident.
It would be helpful to clearly distinguish what you believe is the true state of the world (“math”) and what you think not-quite-rational people need to be told in order to do what you want to make them do (“psychology”).
I do not assume that “the markets always go up”. I merely claim that historically, the market has generally gone up faster than cash over the long run. This was the whole point of the paper linked above that said lump-sum beats DCA, and the same is true when investing a steady stream of income—you will generally do better in the market, so to maximize EV, invest right away when you get the money.
The post above was an attempt to draw that distinction. Are there any points I wasn’t sufficiently clear about?
That is not true. You advise your clients to act a way which implies a specific forecast: that the “markets” will, in the future, outperform other assets, e.g. cash, over the relevant holding period.
Quite right. Any financial advisor who does not do so is being grossly irresponsible.