Weitzman News

Posted May 23, 2022

Q&A: Jamaal Green, Assistant Professor of City and Regional Planning

Planner and geographer Jamaal Green joined Weitzman as a postdoctoral fellow in 2020 and he will join the standing faculty as an assistant professor beginning on July 1, 2022. For the Department of City and Regional Planning, he has taught Land Use & Environmental Modeling and Modeling Geographical Objects, an introductory course on geographic information systems (GIS). In an interview, Green shares insights into teaching GIS, industrial land management in cities, and housing quality in Philadelphia.

You teach an introductory course on GIS. What are the important lessons on the topic you share with your students? 

My approach to Modeling Geographic Objects is different than how folks traditionally have approached introductory GIS courses. I approach it as a researcher. On the first day, I give the students a hypothetical situation. For example, imagine you are sitting in your planning office, you get an email from your manager, and the manager wants to know how many people fit within a particular space. What I tell my students is that you're going to get questions like this, where the deliverable may not necessarily be a map, but you're going to have to use GIS or spatial analysis to be able to answer the question. I ask them to focus a lot on what I call the workflow of that analysis. You get a question, and how do you collect that data, clean that data? If you need to do some kind of spatial analysis on it, how do you make it spatial?

Maps are awesome, but, especially for practicing planners, if you don't have GIS or cartographer in your job title, you’re probably not going to be the one who's going to be producing those maps. It’s going to either be a cartographer, GIS specialist, or even a graphic designer. If you are part of the process, then most likely you're being asked to be part of the data prep process. When working or doing research, you will rarely get already prepared, already spatial data. So, a large part of your actual process of working in GIS, especially within an applied setting, is getting some data and making it spatial. Once it is spatial, then you can do all the cool spatial stuff with it.

I talk a lot about different data types and the basics of what I call “table chopping,” which is when you take table of raw or new data and make them usable for what is needed. This includes being able to subset your data, or getting summary stats, or making new columns based upon some set of functions from other columns, or combining multiple tables. These are all things that you have to do as a matter of course in your GIS workflow, but many GIS courses don't necessarily focus as intently on those parts. Students need to have a good idea about how to work with that data in order to be able to make it spatial.

With a lot of modern GIS software, like ArcGIS Pro, you can do a lot of really sophisticated stuff just by pressing a couple of buttons. So, I don't feel that I necessarily have to spend a whole lot of time going into that software and showing folks how to press those buttons. It's more about trying to explain the steps that we want to take to try and solve spatial problems. The hard part is making the data usable.

You worked for the Department of Human Services in Oregon. Did working for a state agency impact how you teach?

Compared to state agencies, city agencies are probably more comfortable with mapping in GIS because they deal with management of certain kinds of physical assets more. Mapping is seen as a natural thing, especially if you're dealing with planning or public works or environment departments. At the state level, where you're doing more program management and implementation and reporting, people don't know that they want, or need, spatial data at times. When I was at DHS, I would get a lot of questions for relatively basic census stuff or questions about county-level poverty or poverty by tract. One step up from that that, they would come to us after they realized that they needed spatial data on some topic like how many clients are within like some particular geography.

In planning offices, where a lot of people are familiar with GIS, I think it's a problem in a different way. People oftentimes limit GIS to the map. What I tell my students is your final deliverable may not be a map, but you will still have to use a spatial approach.

I try to situate a spatial approach as just one particular methodological approach. If you look at a table in a spatial database, the only difference between a spatial and a non-spatial table is a single column. My spatial database instructor used to love to say, “spatial isn't special, until it is.” I simultaneously want to try and elevate the use of spatial analysis and spatial data, and also I want to demystify it and say it's not this magical thing. It's not going to solve everything, but it can still be very useful for us.

You have done research on industrial land management in cities which suggests that it’s often guided by misinformation. Can you tell us about that?

I became interested in industrial land management through the work of Nancey Green Leigh, who has written about the ways smart growth and the rise of new kinds of infill development leaves no space for industrial land. Industrial land is framed generally as a net negative. That land is often framed as dirty and contaminated. On the economic or political end, it's deemed obsolete. There's this belief that we don't make anything in the US anymore, and that's not true. People say we don’t make anything in cities, and that's also not true. Industrialized land, or land that allows for flex or light-industrial space, also provides a lot of space for the growth of jobs and firms. So, it was very curious to me to see cities enthusiastically converting industrial lands to non-industrial uses, even in areas where their industrial vacancies are low. These are not cities where the industrial districts are bombed out and there are no jobs. We find that even cities with healthy industrial employment bases will convert that land.

In my dissertation, I explored the rise of what I saw as protective zoning policies for industrial land in a handful of cities. I also surveyed planners from the from the 50 largest cities to ask them what about their attitudes about industrial land and economic development. Finally, I attempted an evaluation where I tried to measure the jobs impact for manufacturing and industrial jobs with those protective land policies.

Can you tell us about your current research on housing?

I’m working with Vincent Reina [associate professor of city and regional planning, and faculty director of the Housing Initiative at Penn], looking at housing quality issues for low-income homeowners. We are comparing data from the national American housing survey and the City of Philadelphia’s Basic Systems Repair Program.

Housing quality is really a black box in a lot of cities, especially for owner-occupied properties. We generally assume that if you own your home, you’re good. But for low-income homeowners, especially in the face of years of economic stress in a relatively poor and older city like Philadelphia, deferred maintenance can stack up for years. Your house can literally become a death trap. You don’t have the money to repair it, and the value of your home is probably not great enough that you can get financing. This starts a cycle of degradation.

A lot of people in Philadelphia are aware that this cycle exists, but the extent of it and the burden of substandard housing are not well known. The efforts of the City through the Basic Systems Repair Program to help people improve the state of their housing also helps to stabilize neighborhoods.

Also, we have to note the impact on jobs. Over the past 10 years, the City has spent almost $100 million through the Program. That’s $100 million that would not have gone into the local economy. There is potentially a kind of positive, Keynesian shock for the local economy that stabilizes these folks’ lives and their neighborhoods. There is potentially a virtuous cycle of public investment into greater neighborhood stabilization and local labor market development.