The Pennsylvania Public Interest Research Group (PennPIRG) is the advocacy arm of the Pennsylvania Public Interest Research Group Education Fund and the Pennsylvania state-level affiliate of the U.S. Public Interest Research Group (US-PIRG). It is a multi-issue left-of-center advocacy organization.
Established in 1986, PennPIRG is a state affiliate of the U.S. Public Interest Research Group. PennPIRG, along with the other 46 state affiliates, act as state-based incubators that help push for and implement various left-progressive priorities of US-PIRG. In turn, US-PIRG then uses these state efforts to implement similar laws at the federal level. 
Orienting themselves as a consumer group, PennPIRG weighs in on a litany of issues including those related to taxes, voting rights, and consumer finance. 
PennPIRG is affiliated with the Fund for Public Interest, a clearinghouse for various left-wing advocacy organizations.  The Fund has been dubbed “the liberal sweatshop” for its harsh labor practices.  According to its 2018 tax filing, PennPIRG lists the Fund for Public Interest as an independent contractor for programs and citizen outreach, paying the group $214,741 for their services. 
Since its creation, PennPIRG has been influential in shaping the tax code of Pennsylvania. In 2003, PennPIRG joined United Pennsylvanians, a coalition of community, environmentalist, and labor organizations, which helped craft Democratic Governor Ed Rendell’s “Plan for a New Pennsylvania.” Since public benefits and social programs had bankrupted the state, the plan called for the state’s borrowing ability to be raised by $2 billion and for the personal income tax to be raised from 2.8% to 3.65%.  In recent years, PennPIRG has done work on offshore tax havens and their impact on state revenues, arguing in favor of tax regimes like combined reporting which would increase taxable income by treating the parent and subsidiary companies of a multinational corporation as one single corporation for the purposes of tax collecting. 
When Pennsylvania passed a voter ID law in 2012, PennPIRG created a campaign to educate college students on how the law would impact their ability to vote and worked with college administrators to reissue student IDs that would be in compliance with the law. 
While Penn PIRG is based in Pennsylvania and has mainly focused on issues in the state legislature, the organization has also done work at the federal level. In 2019, Penn PIRG organized a day of lobbying centered around consumer finance in Washington, D.C. with grassroots consumer advocates and other organizations like Public Citizen and Consumer Reports. During meetings with lawmakers, PennPIRG lobbied in favor of further government regulation of the financial sector and for Congress to crack down on the Trump administration-appointed leadership of the Consumer Financial Protection Bureau (CFPB).  Penn PIRG has attacked former acting director Mick Mulvaney and current director Kathy Kraninger for what they view as Mulvaney and Kraninger working to water down consumer finance regulations.  Penn PIRG has also launched a “take action” advocacy campaign for consumers to write their representatives and urge them to prevent the Trump administration from weakening or eliminating the CFPB. 
Ed Mierzwinski is listed as senior director of the Federal Consumer Program at both PennPIRG and US-PIRG.  He cofounded Americans for Financial Reform, which campaigned for the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 that created the CFPB.  He was listed as a “Top Lobbyist” in 2018 by The Hill.