Solution: Economics Meta
Answer: SHUT ELECTRICAL DOWN

Written by Kenny Young

All of the answers in this round are the names of large companies. Those company names are far too long to fit into the blanks provided, but their stock symbols will fit nicely:

ADOBEADBE
CARDINALCAH
DELTADAL
INTUITINTU
MANPOWERMAN
MICRONMU
NIKENKE
PROGRESSIVEPGR
VISAV

The mergers and acquisitions are formed by “merging” pairs of ticker symbols, “acquiring” two extra letters, and then “reorg-ing” the result by anagramming it to make a word with the acquired letters going in the numbered slots. Anagram tools such as Nutrimatic or Qat really help here. Keeping the loop going by using each ticker symbol in two consecutive sets of blanks gives these results:

NKE + V + [LI] = KELVIN
KELVIN
611
V + DAL + [NA] = VANDAL
VANDAL
1318
DAL + MAN + [CE] = MANACLED
MANACLED
85
MAN + CAH + [WT] = WATCHMAN
WATCHMAN
174
CAH + INTU + [TE] = AUTHENTIC
AUTHENTIC
97
INTU + PGR + [UR] = RUPTURING
RUPTURING
310
PGR + MU + [DO] = GUMDROP
GUMDROP
1516
MU + ADBE + [SH] = AMBUSHED
AMBUSHED
12
ADBE + NKE + [LC] = BLACKENED
BLACKENED
1412

And pulling all the numbered blanks into one string yields:

SHUTELECTRICALDOWN
123456789101112131415161718

This pun on “trickle-down economics” is the answer.