The Walt Disney Co. on Thursday said it would buy selected assets of 21st Century Fox, in the latest multibillion-dollar deal of 2017. Also on Thursday, details began to emerge over the Republican tax deal, which includes cutting corporate taxes and a plan to repatriate the untaxed profits of U.S. firms held overseas.

The two events are separate, but point to a longstanding issue in the economy, which is that while economic growth has been steady and solid, companies are using non-organic means to boost their earnings and share prices, a method that may grow less effective with time, and which the tax bill—should it be signed into law—may not alleviate.

The Disney DIS, -3.08% acquisition of Fox FOXA, -3.21% comes at a time when the amount of cash that S&P 500 SPX, -2.37% companies have on hand is at historic highs, totaling 12% of assets, according to Goldman Sachs data.

Read: J.P. Morgan economist says Trump tax plan will create one-tenth the jobs Jamie Dimon says

The passage of the tax bill would boost that total, and the acquisition “shows no one knows what to do with their money,” said Luis Maizel, senior managing director at LM Capital Group, referring to companies. He noted that Disney also announced a $10 billion stock buyback program when it made the acquisition news official.

“There’s no investment in brick and mortar, and if the tax bill does bring cash back, no one will be using it to build a new factory; there will be no rise in demand for steel or anything like that.”

Maizel speculated companies would use any new money in the way they have been, by returning cash to shareholders, either in the form of dividends or buybacks, or to make acquisitions. “It won’t mean anything for organic growth, and little by little the bubble will keep getting bigger.”

The government has claimed the tax bill would spur demand and accelerate hiring, something CEOs have disputed. President Donald Trump’s top economic adviser, Gary Cohn, said the plan would stimulate the economy, and that businesses could hire more and pay better wages with the money they save. However, when a room full of CEOs were asked whether they would make capital expenditures if the corporate tax rate was cut, only a few put their hands up, to Cohn’s chagrin.

The last time there was an one-time tax on the foreign profits of U.S. companies—following the Homeland Investment Act of 2004, which created a repatriation “tax holiday” with an effective rate of 5.25%, as opposed to 35%—buyback activity surged, jumping 84% in 2004 and 58% in 2005, according to Goldman data.

Corporate financial officers have already been spending their money in this way. Buybacks by companies in the S&P 500 rose 15.2% in the third quarter, while dividend payouts hit a record in that same period.

“The tax plan is unlikely to lead to rapid growth and the current state of the economy doesn’t suggest the plan is needed,” wrote Jim McDonald, chief investment strategist at Northern Trust, in a November report. He implied that the primary driver behind the plan was more political than economic necessity. “Republicans are in desperate need of a legislative win and the plan supports their platform.”

Read more: Share buybacks spike—dropping a strong hint at what CEOs plan to do with tax savings

Companies repurchasing their own stock can lift profitability, as profits are measured in earnings per share and reducing the number of shares will have the same mathematical impact as increasing the earnings itself.

Such activity means little for organic economic growth, however, when compared with the stimulative effect of capex spending. In addition, there is data showing a focus on shareholder returns over capital expenditures can lead to share price underperformance.

Since the start of 2016, according to data from Goldman Sachs, companies deploying funds for capex and research and development have outperformed the S&P 500 by 4.4%. They have also outperformed “total cash return” stocks, a trend the investment bank said was likely to continue.

Chart courtesy Goldman Sachs

Goldman expects S&P companies to increase their total cash use by 6% in 2018, “as uncertainty fades.” Of the $2.3 trillion to be spent, the investment bank estimates that 57% of it will be allocated to growth, including capex, R&D, and M&A, while 42% will be returned to shareholders in the form of buybacks and dividends.

“If companies used the money to buy back their stock and for dividends, I don’t think people would be happy with that outcome. I think the market would be fine with it, it wouldn’t be a headwind, but that wouldn’t be the best use of capital,” said Paul Colonna, State Street Global Advisors’ chief investment officer for active fundamental equity, who spoke to MarketWatch in November.

“In terms of improving our long-term competitiveness, I think there’s a fairly compelling story in favor of doing [the bill], but it isn’t as though markets are in need of a rescue,” he added. “Tax reform isn’t about getting the market to a new high; what you want to see, and what we haven’t been seeing, is wage recovery, which I don’t think the bill would have an impact on.”

But even if the economy isn’t in need of a “rescue,” would lower rates make a strong market even stronger, as President Trump has argued in various tweets? It’s difficult to say, although there is some evidence that tax cuts could prove to be detrimental to market performance.

According to a research paper by William Waller, a professor at Carnegie Mellon University, and Anthony Diercks, an economist covering monetary and financial market analysis for the Board of Governors of the Federal Reserve System, the Federal Reserve—rather than tax policy—is the key driver of fiscal effects on equity markets.

“With the Federal Reserve’s more aggressive stance toward economic activity since 1980, we find that tax cuts are associated with lower excess equity returns, despite our findings of positive effects on cash flow news,” the paper read.

The inverse holds true as well, although the paper noted that “tax cuts have larger and more significant effects than tax increases.”

“For the Post-Volcker time period, we find a one standard deviation increase in the tax rate (0.22 percent) is associated with a quarterly positive equity excess return of 0.07 to 0.47 percent,” the paper read.

On Wednesday, the Fed raised interest rates for its fourth time in the past year.