How Much Do They Make? A Systematic Review of Income Generated From Begging

Panhandling income has not been well reviewed, though doing so would be beneficial for several reasons. Understanding beggar income may aid in addressing misconceptions about the activity, clarify the financial motivation for organized or forced begging, and allow for clearer comparisons to other kinds of shadow work like prostitution, binning, or selling drugs. This study presents a systematic review of panhandling income by using Preferred Reporting Items for Systematic Reviews and Meta-Analysis and PROSPERO guidelines to aid in identifying, screening, assessing, and including research that provides quantitative income information about panhandling. Income is adjusted for inflation, and international studies are converted to USD via standard exchange rate and via purchasing power parity values. Ultimately, 38 studies are included for final analysis. The 38 studies are divided into United States specific (n = 15) and all other countries (n = 23). In adjusted 2020 USD, the economic yield from panhandling is most often  $2–$16 per hour, $20–$60 per day, and $200–$500 per month, substantial variation exists. Economic comparisons to other forms of shadow work and future research directions are provided.

However, no study has comprehensively reviewed the amount of money that panhandlers may earn. Smith (2005) has come the closest, though income was of secondary interest as their research related to regulations affecting panhandling throughout the United States. Numerous studies exist that concern panhandling income (Adriaenssens & Hendrickx, 2011;Bose & Hwang, 2003;Goswami et al., 2013) but they typically assess the phenomenon in a localized manner and only provide a cursory review of literature on the subject. The cursory review of literature is also true of studies that examine panhandling throughout a country or across several cities (Lee & Farrell, 2003;Poremski et al. 2015;Snow et al., 1996).
There are several justifications for a review of panhandling income. First, no review currently exists and research reporting panhandling income is disjointed and often contradictory. Begging is an ancient phenomenon (Jamil et al., 2019) and occurs all over the world; numerous conditions affect and are affected by begging. A review on this income will synthesize these studies and provide insight into topics related to begging that may not have been considered otherwise. This synthesis will also help to dispel misconceptions about how much is earned, and potentially shed light on the activity as a form of fraud or financial manipulation of others. Second, panhandling is a type of "shadow work" (Lei, 2013;Snow & Anderson, 1993;Snow et al., 1996) or illegitimate form of employment. By understanding the income generated, it allows for a more thorough comparison to other forms of shadow work like prostitution, busking, 2 binning, 3 selling blood plasma, or others (Lee & Farrell, 2003;Reinhard, 2017;Slesnick et al., 2018). Third, some people who beg are victims of human trafficking and forced to do so (International Labour Office, 1998;Jafri, 2005;Jamil et al., 2019;Tamas et al., 2013). Understanding the amount of money earned through the activity may provide insight into the financial contribution to gangs (Natarajan et al., 2015) or other criminal organizations that may have a financial incentive to traffic persons for this activity.
This study has one research question and two accompanying goals. The research question is how much money is acquired from panhandling or begging? The first goal is to provide a value, at time intervals if necessary, of income likely to be earned through the solicitation of money from other persons on the street. The second goal is to exhaustively locate all relevant studies pertinent to the research question so as to create a document capable of aiding those interested in taking stock of panhandling as a phenomenon. Nuanced topics within panhandling research include repertoires (Lankenau, 1999a), ethnic nepotism (Batovskaya et al., 2000), characteristics of donors (Muñoz & Potter, 2014), issues of self-identity (Abebe, 2008) and humiliation (Lankenau, 1999b), the activity as a form of fraud (Adriaenssens & Hendrickx, 2011), and many others. This study hopes to facilitate the future study of panhandling. This study remains neutral on the legitimacy of the activity and does not approach the topic as an acceptable or unacceptable action.

Background
There are four topics to address before considering panhandling income. First, it is necessary to define the phenomenon of panhandling and begging. All homeless persons are not beggars and all beggars are not homeless. Second, panhandling activities, repertoires, strategies, and classifications are discussed. Many studies that report panhandling income address activities engaged in during the panhandling process (e.g., Lein et al., 2008;Lankenau, 1999a;Tladi, 2017). Third, panhandling locations and a brief overview of the geography of panhandling is provided. This is done because it is unlikely that income is generated randomly irrespective of where one panhandles. In other words, panhandlers are unlikely to earn the same amount of money in residential neighborhoods as they are along arterial roadways next to traffic lights. The fourth topic to address is "law of one price" (LOP) and "purchasing power parity" (PPP). These are economics concepts necessary to mention for comparing income from different countries.
The terms "begging" and "panhandling" are used interchangeably in this study because they are synonymous and used to describe the same activity. The word "panhandling" is used more frequently in North America (Scott, 2003), while "begging" is used more commonly in most other parts of the world (e.g., Jamil et al., 2019;Mansour, 2017;Ndlovu, 2016). Nearly every study about the phenomenon provides variations on its definition, though most entail an in-person request for money or gifts from strangers without material reciprocity (Adriaenssens & Hendrickx, 2011;Qiao et al., 2017). The activity is also often categorized as passive or aggressive, terms that address the manner in which the request is made and general context of the situation (Scott, 2003;D. B. Taylor, 1999;Wamstad, 2007). Aggressive panhandling may be threatening and demanding, akin to robbery. A gray area exists within definitions of begging due to some begging strategies providing a service. For example, beggars who clean the windows of cars and expect payment in return (squeegee men; Dean, 1999;Tladi, 2017), beggars who request "protection money" for a vehicle while it is parked, 4 or beggars who play a musical instrument to facilitate donations (busking; Lankenau, 1999a;Qiao et al., 2017). Research reported in this study will exclude these "squeegee men" (Dachner & Tarasuk, 2002) and "buskers" when reporting income.
Begging strategies and types of beggars also require explanation. This topic is complicated because a physical characteristic of the beggar may simultaneously be used to distinguish the beggar from others as well as a strategy to generate income. For example, beggars may be distinguished as able-bodied or disabled, and the disability may be used strategically (Goswami et al., 2013;Qiao et al., 2017;Sailaja & Rao, 2016). Sarmini et al. (2018) describe accentuating a disability and using shabby clothing as strategic. Batovskaya et al. (2000) distinguishes appearance from behavioral patterns, with the patterns being more closely aligned with the notion of soliciting money in different manners (Lankenau, 1999a). Cupped hands, crying, and storytelling are all examples of common begging strategies (e.g., Meir-Dyiri & Raz, 1995;Qiao et al., 2017). Lankenau (1999a) describes five types of beggars based on their repertoires, servicers, greeters, entertainers, storytellers, and aggressors. Some techniques may generate more income than others (Hagan & McCarthy, 1998, p. 51). The use of a sign conveying a message is also a very common means of panhandling (both Lein et al., 2008, andTladi, 2017, provide lists of observed sign messages among beggars).
Due to the in-person nature of begging, physical location is also worth discussing. The manner in which physical location influences begging income has not been well studied in a quantitative manner, but location selection does not appear random. Panhandling locations could be influenced by the presence of nearby services or certain kinds of establishments. Scott (2003) identifies several locations where panhandlers congregate, such as in front of gas stations, close to public transportation stops (also see Natarajan et al., 2015), along busy sidewalks, exit ramps (Spears, 2013), and along streets by intersections where traffic is periodically required to stop. Spatial analyses often find panhandlers operating close to traffic lights and along arterial roadways where large numbers of motorists can be found (Maiwada et al., 2019;Tladi, 2017). Begging at the same location over time may help establish a reliable "customer base" or enable persons to familiarize a location with a certain beggar (Dordick et al., 2018), both potentially increasing the economic yield over time.
Beggars have indicated the importance of choosing locations that minimize the amount of harassment they receive while simultaneously increasing their visibility to potential donors (Lankenau, 1999a). Location selection may require considerations about risk reduction; reducing the likelihood of harassment from passersby, from other beggars, from police or other security agents, and to avoid regulatory restrictions for places not allowed to have beggars (Wallengren & Mellgren, 2021). Some research has also pointed to informal rules among panhandlers that help govern how they operate with one another. For example, panhandlers attempt to be visible from a distance but also must respect another beggar's claim to a certain spot (Meir-Dviri & Raz, 1995). If this is not done, hostility may occur when one beggar attempts to beg in another's territory (Bajari & Kuswarno, 2020;Reinhard, 2017); territory such as street corners are described as belonging to certain persons who regularly beg there (Stones, 2013).
Because this review includes international comparisons of begging income, it is necessary to briefly address the concept of exchange rates and PPP. PPP and underlying notions such as the "LOP" are cornerstones of international economics and the subject of over 100 years of study 5 (Rogoff, 1996;A. M. Taylor & Taylor, 2004). There are limitations in conventional exchange rates when comparing currency in multiple countries, and one such limitation is the concern that they do not adequately account for the difference in what is purchasable with the same quantity of money. PPP and LOP in essence assert that prices in various countries will be comparable when expressed in the same currency and normalized by the same "basket of goods," where basket is loosely defined as a collection of consumer products (O'Connell, 1998). There is no consensus on the perfect set of goods to compare between countries, and each measure of comparison has its own limitations (Rogoff, 1996). The set of goods used to compare beggar incomes for this study is the World Bank PPP conversion factor, though others could have been used, such as the Big Mac Index (Pakko & Pollard, 2003).
For example, if the regular exchange rate finds that the CAD to USD exchange is 1.36, but a Big Mac, or other basket of goods costs CAD$6.88 in Canada and US$5.71 in the United States, there is a difference between the exchange rate and the implied exchange rate of 1.20 given the cost of the goods. This implied rate indicates fewer CAD required to equal US$1.00 compared to the official exchange rate. In reality, PPP is much more complicated than this and comparisons such as these suffer from numerous issues such as how they do not consider tariffs on goods, nontariff barriers, goods not being perfectly substitutable, service costs, and property rental components (A. M. Taylor & Taylor, 2004). However, government price indexes also have limitations; there is no universally accepted means of cross-country currency comparison (Rogoff, 1996). Given everything already explained and the recognition that both are flawed for different reasons, for international sources reporting beggar income this study provides the USD exchange rate via the U.S. Department of the Treasury, and the PPP adjusted currency using the World Bank PPP conversion factor.

Method
Systematic review (Altena et al., 2010;Dowd & Johnson, 2020;Hwang et al., 2005) was deemed the most appropriate method of answering the research question and attempting to accomplish both goals of the study. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) format was used as a guide for this review (Moher et al., 2009). However, the nature of the outcome desired from studies, quantitative income from begging, is descriptive and not an evaluation or randomized trial as would be typically used with a PRISMA systematic review or meta-analysis. PROSPERO guidelines were also considered when creating this review, though because an economic outcome is desired, the review falls outside of typical PROSPERO review topics. Consequently, while PRISMA and PROSPERO were used to help inform selection criteria, the ultimate goal of this review was to be as exhaustive as possible, not necessarily conform to either set of guidelines.
A defining feature of PRISMA (Moher et al., 2009) is the indication of how many sources were found, in what ways, and how articles were included for final review. Figure 1 provides a PRISMA flow diagram of sources identified, screened, assessed for eligibility, and included for this review. Databases were searched, an institutional library was searched, and the subsequent articles' reference lists were searched to create the 1,903 total records first identified. The databases searched include the Web of Science Core Collection, Medline, EBSCO Host database collection, and ProQuest: Sociological Abstracts. For the database search, key words "panhandle," "panhandler," "beggar," and "begging" were searched within the title of articles; for the institutional library search, in addition to the previous key words, another search was conducted for articles with "homeless" and "income" in the title. Only articles since 1990 were included, and only scholarly journals and academic sources were considered during the database and institutional library search. Modern research that analyzed historical sources or data was not considered. Sources that were not written entirely in English 6 were also excluded. During the full-text screening process, a "cited by" search and reference list search was done to identify sources not initially found through the database and library search. The cited by search and reference list search produced sources other than articles (e. g., books, Dean, 1999;Hagan & McCarthy, 1998;Snow & Anderson, 1993;Spears, 2013). Ultimately after screening and reading entire sources, 38 sources were included.
Identified articles were excluded for many reasons. For example, Rao and Bogaert (1970) 7 has income information but is outside of the date range, and another source had no author information and came from a magazine (International Labour Office, 1998). 8 Jafri (2005) 9 is a nonacademic source not included. Tolkach et al. (2019) 10 was also not included in the final studies because the authors reported the income of persons who use begging to finance international vacations. These "beg-packers" are unique from ordinary beggars in numerous ways, including their advanced educations and previous international travel experience. Lastly, some sources asked nonbeggars about beggars, and when income was suggested by the nonbeggar, it was not included (e.g., Dromi, 2012). 11 For the sake of thoroughness, some unconventional sources were included. Unpublished academic sources such as theses and dissertations were searched (Bowling, 2018;Gaga, 2015;Reinhard, 2017;D. B. Taylor, 1999;Tladi, 2017;Wamstad, 2007). Additionally, secondary sources were included such as Ropers (1988, as cited in D. B. Taylor, 1999. While Smith (2005) is included as one source, the sources cited by Smith are not included in the 38 sources but they are included in the results in Table 1. This was done primarily because Smith (2005) is the most comprehensive review of panhandling income in English to date. Luckenbach and Acosta (1993) are included because they were cited in other studies, and the work presented appears comparable to academic quality. Some government or private sector reports were also included (e.g., Karataş et al., 2016;Tamas et al., 2013) when they provided quantifiable income information.

Limitations
Limitations exist associated with the desire to be exhaustive with the inclusion of sources that report panhandling income. For example, the inclusion of some sources without clear sample sizes (e.g.,Rahmalia & Zulyadi, 2019) prevents the use of a weighting scheme based on their sample size when making comparisons between studies. Because of the wide range of incomes that some panhandlers receive (Conroy, 2001;Goldstein, 1993;Luckenbach & Acosta, 1993;Wamstad, 2007), sources that rely on small samples are susceptible to having extreme values compared to studies that report average values among larger samples (e.g., Bose & Hwang, 2003;Lee & Farrell, 2003;Lein et al., 2008). Similarly, considerable variation exists regarding how income is reported with some studies providing a range (Goldberg, 1995;Jamil et al., 2019), varying measures of central tendency (Bose & Hwang, 2003;Conroy, 2001;Lee & Farrell, 2003), or as an ordinal variable (Malik & Roy, 2012;Mansour, 2017). The decision was made to include all of these studies despite the inevitable challenges raised by comparing such diversely conducted research.
Conventional sample size weighting and statistical tests that evaluate multiple studies typically require listed sample sizes and uniform outcome measures. Several statistical tests exist and are commonly used in meta-analyses (Borenstein et al., 2021). Some commonly accepted tests include the Fisher's combined probability test, or the weighted Z-test (Zaykin, 2011), which cannot be used with the sources included in this systematic review. This study, and other systematic reviews, include studies of varying designs with outcomes of interest measured differently and often rely on other quality assessment tools. PRISMA has a quality assessment check list, and several studies suggest other methods of critically appraising evidence (e.g., Hawker et al., 2002;Thomas et al., 2004). These quality assessment tools are sometimes used for the sake of excluding studies of insufficient quality, and some are formatted specifically for qualitative studies, randomized control trials, or others. 12 There is a second consideration regarding study comparisons and inclusion criteria. This study does not use a simulation model style (see Adriaenssens & Hendrickx, 2011;Muñoz & Potter, 2014) despite the potential benefits of doing so. By using the estimated income from one hour of panhandling (Adriaenssens & Hendrickx, 2011;Bose & Hwang, 2003;Goldberg, 1995), the number of hours panhandled per day (Adriaenssens & Hendrickx, 2011;Malik & Roy, 2012;Tolkach et al., 2019) and the number of days per week (Goldstein, 1993) or per month (DeBeck et al., 2007) spent panhandling, it is possible to estimate an expected daily, weekly, or monthly income from the activity. Because each study reporting income is so varied, it is believed that misspecification of the model is likely. The faulty inputs could greatly affect the findings (e.g., Dean, 1999, p. 38), and this task is being left to future researchers.

Results
Altogether, there were 38 studies identified that fit the criteria and contained quantitative begging income. This represents approximately 2% of the 1,903 original sources. 13 The methodology resulted in diverse sources being found and relied upon for this study. Of the 38 studies, 15 provided income information for panhandling in the United States and 23 provided income information in other countries. Once secondary sources are considered using Smith (2005), there are 27 sources of information for panhandling in the United States. Table 1 provides panhandling income for each of the identified sources of US panhandling income. Ropers (1988) was identified via D. B. Taylor (1999), and all sources from Smith (2005) are indicated at the bottom of Table 1. The table is sorted by Time Interval, beginning with hourly panhandling income, then daily, weekly, monthly, quarterly, and annually.
There were 23 identified studies with quantitative income information for begging outside of the United States. Table 2 provides information on the international studies with begging income. The column 2020 Income (Reported Currency) indicates the currency reported from the study adjusted for inflation to 2020 values; these 2020 values are then used for the following two columns. Table 2 provides two income conversions from foreign currencies to USD. USD Converted Income uses the U.S. Department of the Treasury exchange rate, while PPP Adjusted Income considers the PPP in the different countries. Both are provided because of the concerns about direct currency exchange rates  Karataş et al. (2016) reports the 2-3 hourly income from law enforcement sources, and the daily income is the average amount of money confiscated from 24 beggars arrested while begging over 3 days. not considering the under or overvaluation of currency given the nonuniform purchasing cost of products in various countries (Rogoff, 1996;A. M. Taylor & Taylor, 2004). Among the identified international studies, there were five time intervals; the time intervals were hourly, daily, weekly, monthly, and annually. The reported hourly earnings of beggars in 2020 PPP adjusted USD were $6-$16 (Adriaenssens & Hendrickx, 2011;Bose & Hwang, 2003) with Adriaenssens and Hendrickx (2011) indicating that indigenous Belgium beggars earned two times more than Roma beggars per hour. Daily income overwhelmingly ranged from USD $20 to $60 (Adriaenssens & Hendrickx, 2011;Ahamdi, 2010;Bose & Hwang, 2003;Carlen, 1997, as cited in Dean, 1999Djuve et al., 2015;O'Grady & Gaetz, 2004;Rahmalia & Zulyadi, 2019) but was sometimes less, ranging from USD 1-15 (Goswami et al., 2013;Jamil et al., 2019;Sagbigsal et al., 2019;Stones, 2013;Taiwo et al., 2019). Few studies found greater daily income (e.g., Tamas et al., 2013) but it did occur, such as on good days (Ndlovu, 2016). Weekly income was typically USD 20-70 (Kemp, 1997;Sailaja & Rao, 2016), though could be as much as USD 262.95 (Dean, 1999). Several studies indicate that monthly income for begging is between USD 150 and 500 (Bose & Hwang, 2003;Debeck et al., 2007;Mansour, 2017;Poremski et al., 2015), it was rarely less than this amount (Malik & Roy, 2012). Two studies found that monthly income was USD 697-2,093 (Gaga, 2015;Rahmalia & Zulyadi, 2019), though the sample sizes are unclear for both of these studies. Similarly extreme, "experts" suggest monthly incomes of USD 3,800-4,600 (Tamas et al., 2013). Lastly, the only study to report annual income indicated an average of USD 1,938 per year (Liu, 2008, as cited in Henry, 2009).
Numerous studies exist that consider panhandling income as a matter of primary importance (Bose & Hwang, 2003;Goswami et al., 2013;Spears, 2013) or report it as a matter of peripheral importance (Lankenau, 1999a;Lein et al., 2008). Smith (2005) is vital for having compared reports of beggar income analytically in a manner not done previously. Adriaenssens and Hendrickx (2011) is similarly important for being the most comprehensive consideration of calculating income with both cash donations and gift donations. The diversity of English-language studies found with data from various countries was also unanticipated but useful for understanding how the activity and income may fluctuate from country to country.
Begging income depends on the time interval considered, such as over the course of hours, days, weeks, or months. Influential observations exist, with individuals reporting income many times greater than the average amount (Goldstein, 1993;Luckenbach & Acosta, 1993;Ndlovu, 2016), but many of the studies with large samples report averages much lower (Conroy, 2001;Lee & Farrell, 2003;Poremski et al., 2015). However, after adjusting U.S. studies for inflation and adjusting non-U.S. studies for inflation and converting income by considering the PPP of each country, some general income conclusions exist. Hourly income tends to be USD 2-$16 (Adriaenssens & Hendrickx, 2011;Bose & Hwang, 2003;Goldberg, 1995), daily income USD 20-60 (Ahmadi, 2010; Lein et al., 2008;Luckenback & Acosta, 1993;O'Grady & Gaetz, 2004), and monthly income USD 200-500 (Bose & Hwang, 2003;DeBeck et al., 2007;Lee & Farrell, 2003;Mansour, 2017;North & Pollio, 2017;Wamstad, 2007). Among the 38 studies, exceptions to the aforementioned conclusions are available (Gaga, 2015;Poremski et al., 2015;Rossi et al., 1986, as cited by Stark, 1992;Tamas et al., 2013), but the listed ranges still represent the most comprehensive answer available for the research question. It is most comprehensive in that there is a reliance on standardized income from dozens of sources found through the systematic search of all English-language articles written after 1990 that list begging income. Additionally, by attempting to be exhaustive in the search for this information, it is hoped that future research on begging may more easily find these sources of information.
A comparison that could be made regarding these income conclusions is how they measure against typical U.S. median income and what is purchasable from begging. Extrapolating annual begging income from 12 months of begging may produce annual begging income estimates of USD 3,600, from monthly averages of USD 300 (consistent with 2020 income inflated values from Lee & Farrell, 2003;North & Pollio, 2017;Wamstad, 2007). Average annual U.S. income estimates vary, for example, between the U.S. Census Bureau and the U.S. Department of Housing and Urban Development, but the U.S. Census found household median income to be approximately $69,000 (Semega et al., 2020). Extrapolated begging income thus represents 5.2% of that annual income estimate. Compared to the $300 monthly begging average in the United States, the average cost of a studio apartment may be $932 per month (Statista Research Department, 2021) or three times more money than is typically produced through begging for one month. The cost of purchasing a single Big Mac per day for 30 days is $170 (The Economist, 2021), or 56.6% of monthly begging income. Transportation costs vary depending on type of transportation and distance traveled, though average passenger fare on a U.S. city bus is approximately $2 per trip (U.S. Department of Transportation, 2020). If two trips are necessary per day for 30 days, this requires $120 or 40% of average monthly begging income. A monthly cost of living estimate of $934 in the United States that excludes rent but includes transportation, clothing, food expenses, utilities, and leisure (Numbeo, 2021) is more than three times what is produced through monthly begging income on average. Individuals who engage in begging may experience substance dependency (DeBeck et al., 2007;North & Pollio, 2017), though estimating monthly costs of this are complicated by considerations such as which substance, local market costs, and level of dependency. It is also important to remember that individuals who engage in begging also often engage in other forms of shadow work as well (Lee & Farrell, 2003).
These income conclusions suggest that panhandling competitively generates money compared to other forms of shadow work. This provides support for the popularity in panhandling among some homeless samples (e.g., Ferguson et al., 2018;Lee & Farrell, 2003;Snow et al., 1996). Panhandling seems to provide more income than binning (recycling, bottling) on average (Conroy, 2001;Djuve et al., 2015) and more income than selling one's blood (Conroy, 2001). However, it typically provides less money than busking, selling items, or sex work (Conroy, 2001;Kemp, 1997;O'Grady & Gaetz, 2004;Poremski et al., 2015). While begging is often described as extremely humiliating (Djuve et al., 2015;Lankenau, 1999b), it is an activity that can be done daily, which allows for consistent income. Theft, selling drugs, and burglary have all been found to generate more money than begging on average (O'Grady & Gaetz, 2004;Poremski et al., 2015), but they likely present greater legal risk. Selling your own blood is also an activity that cannot be done every day. Some activities are more sustainable and some activities provide more money in a shorter time. Prostitution may provide $100 an hour but presents other issues (Poremski et al., 2015).
Perhaps more concerning are implications for human trafficking and forced begging. Panhandling is rarely thought of as a controlled activity in North America; concerns commonly exist in Asia, Africa, and Europe (International Labour Office, 1998;Jafri, 2005;Jamil et al., 2019;Tamas et al., 2013) that beggars are forced into the activity and provide their earned income to handlers, akin to pimps in sex work (O'Grady & Gaetz, 2004). Children who are told by their families to beg for money are also considered forced beggars (Jamil et al., 2019). Human traffickers may not be at substantial legal risk for forcing persons to engage in begging (Tamas et al., 2013), which further encourages this type of exploitation. Begging income is often found to generate less income than "regular work" (Kemp, 1997;Poremski et al., 2015), but this study finds that on an hourly and daily basis, it still provides an appreciable amount of money (Adriaenssens & Hendrickx, 2011;Lein et al., 2008). It is unknown how commonly forced begging occurs in different countries, but this study suggests that beggars may earn an amount that warrants further research regarding economic incentives for exploiting beggars. This is one of many considerations for future research.
There are several future directions of research related to understanding panhandling income. The explicit delineation of panhandling strategies as a means of deducing which are most economically effective (Batovskaya et al., 2000;Hagan & McCarthy, 1998;Lankenau, 1999a) is one such example. Another is determining the economic value of pristine location selection among panhandlers. Given the belief that panhandlers are not acting randomly in where they solicit money (Scott, 2003), it is possible that city planners or officials may be able to adjust architectural designs in order to discourage begging in certain places, especially if more were known about the specifics of location selection. Additionally, this study assessed the income generated from panhandling, but not necessarily how much money panhandlers earned from all sources (O'Grady & Gaetz, 2004;Poremski et al., 2015) or how the money was spent (North & Pollio, 2017;Wamstad, 2007). Lastly, there are numerous qualitative studies not considered for the quantitative synthesis used in this article, but those studies provide unique insights into the everyday experiences and interactions that beggars have with donors (Batovskaya et al., 2000;Lankenau, 1999b;Tladi, 2017). An exploration of those studies may provide greater insight into other dynamics during charitable exchanges between givers and receivers.
Several implications exist regarding the income found to be generated through panhandling. First, and contrary to the assertation that beggars typically make large sums of money (e.g., Borland, 2009;Hill, 2009), this study dispels the myth that individuals will reliably generate large sums of money from the activity. Different kinds of panhandling repertoires or unique strategies (Hagan & McCarthy, 1998) may produce large sums of money, but it hardly seems like a reliable source of income one would want to have to rely upon. Second, a great deal of money may not be generated, but panhandling still produces enough income to warrant policies and awareness of begging, forced begging, and persons trafficked to beg for others (International Labour Office, 1998;Jafri, 2005;Jamil et al., 2019;). Literature posits that panhandlers may be the subject of abuses from both homeless persons and nonhomeless persons (Wamstad, 2007), and compounded with the notion that individuals may be forced to engage in the activity, this depicts a grim reality for individuals who may receive scorn from passersby for "receiving a free handout." While it is outside of the scope of this article to suggest laws or widespread policy for panhandling (see Blomley, 2007;Ellickson, 1995;Mabry, 1994;Swanson, 2007), criminalization and harsh deterrence policies could threaten the quality of life for people who beg.
Danila, your work translating research from Russian into English provided an understanding into Russian begging that would not have been available otherwise. Carlos, thank-you for providing insights into El Salvadoran shadow work. Nick, thank-you for providing access to some of the sources used in this study.

Declaration of Conflicting Interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/ or publication of this article.

Funding
The author received no financial support for the research, authorship, and/or publication of this article.

Daniel Reinhard
https://orcid.org/0000-0003-2067-8962 Notes 1. Vocabulary used in this study are consistent with the published literature and not meant to be dehumanizing or pejorative. Terms such as "beggars" (Jamil et al., 2019), "squeegee men" (Dachner & Tarasuk, 2002), and so on are used here because of prior literature. This study is not capable of adequately addressing linguistic concerns regarding "person-centered language." The most common term used in the United States for a person who begs for money is "panhandler" (Scott, 2003). 2. "Busking" is a term used to refer to individuals who play a musical instrument in public and accept donations. 3. "Binning" is a term used interchangeably with "recycling" and "bottling" and refers to an activity of collecting used materials that can be exchanged for income at depots and warehouses. 4. Personal communication with C. Ponce (2020). It was indicated that in El Salvador after a vehicle is parked, an individual may approach the driver and request $1-$2 to ensure nothing bad happens to the vehicle while the driver is away. This constitutes a unique form of shadow work compared to what has been addressed in the English literature (Lei, 2013;Reinhard, 2017;Snow & Anderson, 1993). 5. It cannot be overstated that the complexities discussed in economics and econometrics regarding purchasing power parity (PPP) are not capable of being thoroughly addressed in this study. Absolute and relative PPP are not discussed here, nor is an explanation for PPP data series over time. For example, decades of research by econometricians focuses on overcoming unexplainable PPP series fluctuation and nonstationarity (Rogoff, 1996;A. M. Taylor & Taylor, 2004). 6. Some publications (not included in Table 2 Rao and Bogaert (1970) indicate that in 1969 currency, the median income of beggars who responded was between 0.51 to 1.00`per day, though the authors indicate that beggars provided numbers lower than the true amount. 8. Children forced to beg are said to "hand their agent" US$20 or more per day in 1998 currency (International Labour Office, 1998, p. 18). 9. Jafri (2005) reports on a survey of 10,466 beggars in Hyderabad, India. The survey found that 47% of beggars earned 900-2000`per month in 2005 currency. Among other results, they also found that 12% of beggars were forced to beg by their parents. 10. Tolkach et al. (2019) found that respondents (n = 8) earned an average of HK$300 per day in 2017-2018 currency though they found a large range both hourly and daily.
11. Dromi (2012, p. 860) indicates that during an interview, one respondent suggested that "[beggars] can probably make $20-$30 a day if they want to." 12. Because quality assessment was not used for this study to exclude sources of information that provide panhandling income (e.g., books, government reports, qualitative or quantitative studies), more detailed information about quality assessment for each source of information is not presented here but available upon request. 13. This is consistent with other systematic reviews on homeless topics. For example, Altena et al. (2010) used 0.7% of their originally identified sources (11 of 1,547) and Hwang et al. (2005) used 1.6% of their sources (73 of 4,564). There is no best practice for a quantity of used sources because more or less research will be available depending on the topic; it is possible to find 0 sources for novel topics or hundreds of sources for popular topics.