A report fromthe Ubran Institute hypothesizes that local political rhetoric andlocal news coverage likely shaped people's understanding of themarketplace. (Photo: Shutterstock)

2018 has been a mixed bag for the Obamacare marketplace.

A new report by the Urban Institute shows thatwhile overall enrollment declined 3.8 percent fromthe year before, no doubt at least in part due to the repeal of theindividual mandate, sign-ups actually increased in 15 states.

The analysis identified a number of different factors shapingthe outcomes in five different states: Rhode Island, Washingtonstate, New York, West Virginia and Louisiana.

Related: Prepare for double-digit ACA premium increases in2019

Rhode Island, Washington and New York saw enrollmentincreases of 12.1 percent, 7.8 percent and 4.2 percent,respectively. Meanwhile West Virginia and Louisiana experienceddramatic enrollment declines of 19.5 percent and 23.5 percent,respectively.

In three of the states –– Rhode Island, Washington state andLouisiana –– state officials instructed insurers to focus theirrate increase on silver-level plans ("silver-loading") becauseit is the cost of those plans that determines the size of federaltax credits.

"The tax credit increase caused by silver-loading made gold andbronze plans significantly cheaper not only for consumers whoqualified for cost-sharing reductions, but for all consumers whoqualified for premium tax credits," write the study authors.

The study also drew a link between the amount of competition in the ACA marketplaceand enrollment. When there is more competition, there is moreadvertising and therefore more awareness among consumers of the ACAexchange.

State efforts to promote or encourage enrollment, includingthrough social media campaigns, appeared to have had animpact, the study found.

Finally, the report hypothesizes that local political rhetoricand local news coverage likely shaped people's understanding of themarketplace.

In Rhode Island, Washington state and New York, local leadersengaged in prominent efforts to defend the ACA and promote itsaccomplishments. In states where political leaders loudly opposedthe ACA and supported federal repeal efforts, many consumers likelybelieved the law had been repealed and that ACA marketplacecoverage was no longer available.

Granted, Louisiana and West Virginia aren't the best examples ofanti-Obamacare states, since Louisiana's governor was elected on aplatform largely based on expanding Medicaid and West Virginia,despite total GOP control of state government, has expandedMedicaid in the early days of Obamacare and has not takenmeaningful steps to undo it.