McKinsey thinks that sector specific supercycles/boom bust account for 1/3 of the decline in labor's share of income in the United States, also finds that 75% of the decline in labor share btw 1945-2016 took place btw 2000-2016

"....In this paper, we look at the relative importance of different factors in the United States through a focus on the complement of the labor share decline—that is, the rise in capital share of income. We decompose this into the role of depreciation, capital-to-output ratios, and returns on invested capital and link them to a microanalysis of 12 sectors.While our findings confirm the relevance of the most commonly cited factors, they also suggest that other trends often absent from the current debate played an even more central role. Key findings: The labor share of income in the US private business sector declined by about 5.4 percentage points between the periods 1998 to 2002 and 2012 to 2016. Without such a decline since 1998, average worker pay might be about $3,000 higher per year in real terms. The decrease between 2000 and 2016 accounts for three-quarters of the overall decline in the US labor share of income since World War II. Our analysis finds that the fall accounts for 18 percent of the gap that opened between median wage growth and historical productivity growth. Weak productivity growth explains 50 percent of the gap, while disproportionate distribution of income gains to highly paid workers accounts for 19 percent. Twelve sectors that make up about one-third of employment and 44 percent of economic output explain the overall decline in labor share or increase in capital share. These tend to be more globalized, more digitized, and more capital-intensive than the overall economy, but also include high-employment services like wholesale and retail. Eight of the 12 sectors experienced faster than-average wage growth, in most cases supported by above-average productivity growth. Nevertheless, almost all of these sectors have experienced a decline in labor share of more than five percentage points. In analyzing the various hypotheses behind the labor share decline across these sectors,we find that a set of supercycle and boom-bust effects appears as the main driver, accounting for one-third of the total decline since 1998. The commodity supercycle notably increased profits in the mining sector, while the real estate boom temporarily increased capital stocks in the sector and its weight in the total economy. The second-most important factor (26 percent of the decline) is rising and faster depreciation, due to higher capital stocks and a shift to intangible assets with shorter life cycles.For example, computer and electronics manufacturing raised the share of assets from intellectual property products in total capital and, with it, depreciation. Pharmaceuticals and chemicals also used more intangible capital and experienced higher depreciation. Superstar effects—which see a small proportion of large firms capturing a disproportionately larger share of economic profit than their peers—along with industry consolidation appear to explain about 18 percent of the decline, including in sectors such as telecommunications, media, and transportation. Capital substitution of labor and automation could underpin 12 percent of the labor share decline, according to our estimates. Globalization and decreased labor bargaining power, which affected the automotive sector among others, account for the remaining 11 percent.While further research will be needed to confirm and refine these findings, they already highlight some trends and implications. First, it is clear that economic context matters and a decline in labor share is not, per se, “bad.” For instance, while the shift to intangibles has negatively affected the labor share, it can raise productivity. Our research highlights the importance of driving productivity growth as the most important determinant of wage growth. Improving human capital will also be essential. Raising investment rates could have a much higher positive effect on productivity and wages than the historically smallish negative impact of capital deepening on the labor share. Our research suggests that labor share declines could continue but at a slower pace.Commodity cycle effects should taper off, and offshoring for reasons of labor-cost arbitrage is declining. The ongoing shift to intangibles will likely continue to raise depreciation, however. Superstar effects also have grown stronger, although policy changes or hypercompetition might alter the trajectory. Capital substitution and technology deployment look set to continue or accelerate, with significant uncertainty around the elasticities of labor substitution versus complementation as a critical determinant of whether that will be good or bad for the labor share. Our research on automation suggests that more occupations will be complemented than substituted...."

James Manyika, Jan Mischke, Jacques Bughin, Jonathan Woetzel, Mekala Krishnan, and Samuel Cudre, "A new look at the declining labor share of income in the United States," McKinsey & Company, May 2019, https://www.mckinsey.com/featured-insights/employment-and-growth/a-new-look-at-the-declining-labor-share-of-income-in-the-united-states

New NBER paper provides evidence to how the market gradually builds institutional capabilities--workers are willing to take a pay-cut to get valuable on-the-job training. The paper uses data from Glassdoor and finds IT workers seek firms that are using emerging IT systems and are willing to take a haircut for that job.

"...This paper provides evidence that IT workers prefer employers that invest in emerging IT systems, and this is in part because they can acquire valuable skills on the job.Although prior studies have examined how IT assets affect performance, we show that those investments can influence firms’ competitiveness in the market for high-tech labor. In fact,IT investment may derive some of its performance value because workers are attracted to firms with a superior engineering brand. For a given wage, employers using new technologies can attract higher-productivity technical labor. These effects are large enough to be interesting. For a firm in which engineers account for a large percent of the workforce, a 2% to 4% reduction in the wage bill is a powerful financial incentive. Results from the productivity literature suggest that the total share of IT investment for Fortune 500 firms is 3% to 5% of total expenditures. Therefore, a reduction of a few percentage points in the wage bill (which can often account for 70% to 80% of total spending) can offset a large fraction of a firm’s IT costs. Of course, this does not imply that all firms should adopt emerging IT systems. These investments are associated with higher churn, which is itself costly, and firms differ in the costs they face when first adopting these systems. Our findings suggest only that ceteris paribus, firms with stronger engineering brands, in terms of technology and culture, can attract higher quality technical labor for a given wage. Our findings have several implications. Competition for IT labor has been a subject of policy discussion for a generation. Firms’ IT choices can be an important determinant of retention, and may be one reason why poaching in high-tech markets often requires higher wage premiums than other markets. Where workers feel that their skills are depreciating, they may be harder to retain than in environments where they learn new skills that will be valuable for their future careers.The argument that workers derive value from acquiring transferable skills has additional implications. Because being rewarded for these skills requires switching employers, workers may place greater value on IT experience in markets where mobility is unfettered by non-compete policies. This implies, in turn, that firms have greater incentives to adopt emerging IT in markets without mobility restrictions because they can capture more of the value they provide to workers through this channel. Finally, the heterogeneity of our findings by experience level suggests that IT factors can influence how different age workers sort across firms, which may be important given the many diversity concerns that high-tech firms face. There are caveats to our study. It would be valuable to know whether the results differ for workers who are not actively seeking jobs. Our data are also from a short panel, so we do not take a position on whether these effects are idiosyncratic to the time period we study or whether they are more broadly generalized to IT-enabled change. A more encompassing test might analyze data from more than one IT diffusion wave. Indeed, in the long run, firms and technology vendors may change the nature of their actions in a way that changes these relationships. There remains significant scope for work in this area. How firm characteristics, beyond IT investment, influence IT learning and IT wage structure merits further study. Moreover, how IT workers acquire skills, how these skills are rewarded, and how they depreciate all have implications for the IT labor force. Those implications include who chooses to be an IT worker and the wages they earn. These questions have received relatively little attention in the academic literature, but their answers are becoming important for workforce policy and for managing technology in a competitive labor market...."

Prasanna Tambe, Xuan Ye, Peter Cappelli, "Paying to Program? Engineering Brand and High-Tech Wage," National Bureau of Economic Research, February 2019, https://www.nber.org/papers/w25552

"... The three main takeaways from a broad analysis of cross-country firm-level patterns are that (1)market power has increased moderately across advanced economies, as indicated by firms’ price markups over marginal costs rising by close to 8 percent since 2000, but not in emerging market economies; (2) the increase has been fairly widespread across advanced economies and industries, but within them, it has been concentrated among a small fraction of dynamic—more productive and innovative—firms.... As regards performance, the top 10 percent of firms in the markup distribution are, on average, about 50 percent more profitable, more than 30 percent more productive, and more than 30 percent more intensive in their use of intangible assets than the other 90 percent (Figure 2.5, panel 3).....and (3) although the overall macroeconomic implications have been modest so far, further increases in the market power of these already-powerful firms could weaken investment, deter innovation, reduce labor income shares, and make it more difficult for monetary policy to stabilize output. Even as rising corporate market power seems, so far, more reflective of “winner-takes-most” by more productive and innovative firms than of weaker pro-competition policies, its challenging macroeconomic implications call for reforms that keep future market competition strong...."

Wenjie Chen, Federico Díez, Romain Duval, Callum Jones, and Carolina Villegas-Sánche, "World Economic Outlook, The Rise of Corporate Market Power and It's Macroeconomic Effects," International Monetary Fund, April 2019, https://www.imf.org/en/Publications/WEO/Issues/2019/03/28/world-economic-outlook-april-2019