"Why are they doing this?" Tom asked.
"They're destroying the groves to keep prices high," Pa said. "They don't care about the trees or the people who work here. All they care about is money."
--The Grapes of Wrath
edit: this is the quote I was looking for at first
"...Did you ever hear of the Farmers’ Association?”
“Why, sure.”
“Well, I belong to it. We had a meeting last night. Now, do you know who runs the Farmers’ Association? I’ll tell you. The Bank of the West. That bank owns most of this valley, and it’s got paper on everything it don’t own. So last night the member from the bank told me, he said, ‘You’re paying thirty cents an hour. You’d better cut it down to twenty-five.’ I said, ‘I’ve got good men. They’re worth thirty.’ And he says, ‘It isn’t that,’ he says. ‘The wage is twenty-five now. If you pay thirty, it’ll only cause unrest. And by the way,’ he says, ‘you going to need the usual amount for a crop loan next year?’ ” Thomas stopped. His breath was panting through his lips. “You see? The rate is twenty-five cents— and like it.”
“We done good work,” Timothy said helplessly.
“Ain’t you got it yet? Mr. Bank hires two thousand men an’ I hire three. I’ve got paper to meet. Now if you can figure some way out, by Christ, I’ll take it! They got me.
Surely in many cases neither farmers producing cash crops nor the countries they are based in are able to 'invest in the future', but rather are trapped by past debts and limited options.